Ok, even through I'm not a professional Reviewer or anything, but I'll give it a try:

Earth/Water/Fire Dragon: On first sight, these cards seem pretty balanced, however they should be (semi-)limited once if this archetype makes it into the game. The Reason: You don't discard cards from your hand, you DESTROY them, triggering the effects of the big dragons and other cards which trigger whenever they are destroyed.

Wind/Darkness/Light Dragon: These cards are entirely ok. There is neither a reason to change them nor to limit them.

Dragon of the Infernos/Earthly Creation/The Hurricanes: They can special summon themselves everytime a spell effect destroys them, have decent ATK/DEF and destroy a card everytime they are summoned (even when it's by their own effects). I think this is a little bit overpowered. To be serious, I wouldn't wonder if they get limited.

Dragon of the Seas/The Heavens/The Abyss: I really like these cards, as they do summon themselves, but don't automatically screw your opponent when they do. "The Abyss" even excludes his own effect, making him way more balanced than the other three dragons who trigger their effects through summoning. "The Seas" is my favorite dragon, as it punishes the enemy for destroying it the only way he can: By battle! A genius card! "The Heavens" is a healer who is good, but not too powerful on his own. With "The Tyrant Neptune" I would consider him even a very good healer.

Arunia, the Dragon of Chaos: Wow, just wow. You destroy cards you get back anyway and which screw your opponent when they come back while screwing your opponent... At least skip your entire battle phase, please.

Maxwell, the Dragon Knight: This card seems kinda counterproductive: It stopps your dragons from being destroyed even through "The Inferno" etc. depend on being destroyed. If you would create more cards which need "Maxwell" on the Field, I would be able to see the use of this card.

A Dragon's Sacrifice: You destroy 1 Dragon from your hand and one from you field and get two cards? So basically, you lose your field presence for 1 round and special summon two cards in your next standby phase, possibly destroying your opponents cards in the process? In my eyes, this card is a better version of "Reckless Greed" and I think it's kinda OP. How about you discard the Dragon from your hand, instead of destroying it?

Bond between Trainer and Master: This card is really tricky:
If "Maxwell" is on the field, the summoned dragons are not destroyed during the end phase.
If "Maxwell" is in the graveyard, the dragons are destroyed and summon themselves in your next standby phase... I don't say this card is OP, but I got to say that I have a bad feeling about this one...

Dragon Realm Ritual: A ritual card how it should be: Short, simple and sensemaking.

Dragon Recon: It says discard, so I don't have any complaints about this card.

Dragon's Lair: The card itself is nice, but not very strong in my eyes. I see no real reason to choose this card instead of "Ècole de Zone". How about removing the discarding? The tiny Dragons do this way better. On the other hand, your dragons gain 500 ATK/DEF, which makes them nearly indestructable, as card effects are only a temporary solution.

Dragon's Might: A good equip card. You will very likely get at least +900 from this card, but in comparision of other cards, this one is very balanced.

Dragon's Roar: Again, it is destroyed during the end phase, meaning that it will return next standby phase... On the other hand, you pay half your life points, so it is not OP or anything.

Sacrifice to the Dragonic Race: Why would you not want your dragons destroyed by card effects, or even pay life points for it? I would rather wait a turn for my OTK and activate my Dragons self-summoning effect instead of paying this much. How about halfing the price?

In general: Your Dragons are a good archetype, but sometimes they support each other TOO much to be a fair one. Together with "The Tripper Mercury", these cards are incredibly dangerous. And with all that discarding and cards which negate the effects of cards special summoned by their effects, a "Void Ogre Dragon" might not be so far away as it seems...

Greetings
VB99

i can actually explain the reasoning behind some of the card's being "OP". i play tested them against some of the meta decks and i came to the conclusion that these cards are too slow to be able to really do anything much without critical thinking. with that being said, i can understand as to why you would think some of the cards are too ridiculous, and i'd like to share my reasoning behind making their effects the way they are.
 when i made the big dragon's i took into consideration that just popping monsters would be too ridiculous, so i gave it the atk/def limit, and made it to where only one of each type could be brought back by that effect to keep them from being abused too hardcore and for the sake of not making them a field nuke and making a pop lock (see high avatar garunix/phoenix). also, i don't think the idea of using The Tripper Mercury in this deck would work because the card has to have an original attack to be able to pop the monster, and he only modifies the attack, not makes the original attack 0 (i don't think he does at least). adding on to the fact that they can't be used for the summon of anything other than a fusion summon makes it to where you have to use just the deck, and if you need to use a synchro or xyz monster to have an answer, you can't do much about it when you only have these on the field, and that makes it balanced in my opinion.
 Maxwell was made with the intention of having a big beater for the deck, but also made it to where you couldn't abuse the effects of the dragons to try and make a lock with the dragons themselves, so i made it to where they couldn't be killed to help not abusing their effects. i also tried to make the deck to where you would want to use this card (hence bond between trainer and master) and still make it a viable card.
  Arunia seems to be your biggest gripe (which i can understand as to why, the effect seems really good at first site) but the reason i had him only not be able to attack is because when you get him out, you won't have that much wiggle room to use his effect too ridiculously, and would only be able to pop 1-2 cards most if you get him out early game. he was a card that i saw as the get around for big monsters/problem cards, while at the same time, not causing too many otk's. i'll probably modify him to where you can't summon other monsters for the rest of the turn after you use the effect to prevent other monsters to come into play and keep you thinking on when to use the effect.
 And lastly, sacrifice to the Dragonic Race was made with the idea of getting rid of cards that can get around their effects of special summoning themselves. (cards that bounce them back to the deck, sends to the grave instead of destroying, etc.) while also having the drawback of losing a set amount of life points to keep it from being abused.
 In conclusion, i can see where you're getting at with the deck might be a bit much, but it can only be effectively used in the hands of someone that actually knows what they're doing with them. thank you for your review though, i appreciate the feedback!

Mercury can also swap monsters in attack position. Basically, Mercury switches monsters with low ATK in attack position, giving your dragons good targets to inflict battle damage.
Maxwell might needs to be summoned correctly to make the bond activateable, but he doesn't need to remain there. The absolute worst case scenario would be The Tyrant Neptune + Dragon of the Heavens.
The Sacrifice makes sense now that you have explained to me why you ned this card.
Arunia is very strong in my eyes since I see it like this: Arunia gets summoned, Arunia sacrifices 1 Dragon and itself to destroy two monsters your opponent controls and in the battle phase, you can attack your opponent without any need to worry about your opponents traps, as such cards can't affect your dragons this turn.
My biggest gripe, however, are the cards I mentioned first: Earth/Water/Fire Dragon.
You destroy 2 dragons from your hand and can special summon them next turn. The card that will be negated can also be a card you control.
Example: Earth Dragon. You special summon one Dragon, he activates his effect, you negate his effect and destroy two dragons from your hand. The result: Your next Standby Phase will result in up to three special summons, generating up to three effects.

Greetings
VB99

i'm gonna be completely honest...i didn't realize that could become a play until you pointed out to me xD. i'll probably change his effect to discard 2, and make it to where you have to tribute the fire and water dragons along with the destruction effects just in case i missed something else with them lol. let me know if you find anything else like that, i really appreciate the help with balancing these lol

Tributing them seems a bit much if you ask me. Once per turn would be enough restriction, maybe even once per Dragon-Type-Monster you control?
My problem with the tiny ones is the destroying of hand cards, but if you change that to discarding, I have no objection anymore

Greetings
VB99

idk about the once per dragon-type monster restriction, seeing as how you can only use the effect 3 times a turn anyway, and even then you'll need to build up better hand advantage as well in order to use their effects again, it just seems like it would destroy your hand advantage too much (or at least bait the player using this deck out to do so). tributing them to where their effects can only be used once while on the field would make them a lot more balanced than making the restriction of once per turn (in my eyes at least.) it'll also prevent a void oger-esque lock as you previously mentioned.

They are your cards, so it's your choice.
Talking about Void Ogre Dragon: It's very likely players will use your cards in combination with this monster and decoy dragon. The reason: Decoy dragon is a dragon type and it's effect fit's the entire theme, as it is a dragon-type and special summons dragon of level 7 or higher, a criteria all of your big dragons fit. Once this card is inside of your graveyard, you can summon junk synchron to revive it. As all of your tiny dragons have level 4, discarding one using Level Lifter gives you the perfekt material for Void Ogre Dragon.

Greetings
VB99