- If I can give an opinion, I think the dragon's size is too big (at least please make not to exceed the screen). Maybe if you want to be that big, you can make it that way when the Charge Bar is fully loaded, that way it will grow in a few moments (Maybe after the charge bar is ready).
Trust me, the original dragon model was even worse, size-wise. This is only 0.8-times the size.
I have considered scaling the dragon even further down in size, but I am concerned that it won't seem like a "mature" dragon if I get it too small.
As for the charge-bar, adding one is item one-million-and-two on my to-do list for this class—but the mechanic I was thinking of would be a "stamina" bar, which reduces combat effectiveness the more it is filled. The dragon's massive firepower should come at a cost, no?
EDIT: I scaled it to about what I initially felt to look perfect during active play. I too am annoyed that the character-select screen seems to cut off half the dragon's torso.
I am considering scaling the dragon down to 0.6-times instead of 0.8-times (which should still be large, but not blot out a third of the screen). What do you think?
- For variations maybe you can give a colors on the dragon.
I have already made a dozen skin variations for the dragon model. Unfortunately, actually making them selectable options is not nearly as easy for a class as it is for a pet.
(Wardrobe-subsystem compatibility is a nightmare for monster classes.)
- For when you equipped melee weapons, the 1h weapon currently looks the best rather than 2h weapon. But it seems to be more suitable for a dragonoid than a dragon. 
Yeah, the weapon scaling is more than a little temporary (I just arbitrarily assigned them to 1.5-times their original size). And the build I am currently testing uses a nicer-looking model for the (elemental) starting weapons.
- Some of the Claw weapons also look good for those that have quite long razor claws (but still not look natural). Maybe you can make a dragon's claw covered with aura, to make the dragon's claw look a little longer (the color of aura depends on the element you give). 
Good luck with that. I have not the slightest clue how to take a piece of a mesh like that.
See above on what I am doing for the starting claws. The model I changed to looks considerably better.
- Long-range weapons do not seem to fit.
No kidding. There is a reason I did not make the class able to use them (with the exception of wands).
- But I found something nice when I tried to use Wand weapon. It's just looks weird when holding it. But the animation effect when dragons attack using wand is very good. Especially when a fireball is thrown from the hands of a dragon. I'm wondering if a dragon has passive skills where sometimes he can also fire a fireball attack might be good (not limited to fireballs only). 
That is why I made the wands usable.
Technically, the animation is pretty much the same as the standard melee attack. The dual-wielding animation for wands simply merges both hands in the same animation-file (with compressed timing).
As for passive skills, I am currently planning to add elemental damage of all types to most skills (with a high-level bonus adding poison damage), but with additional costs (such as reduced attack speed).
EDIT: My primary focus at the moment is skills for this class. Once I have a proper suite of skills for a "dragon alchemist", then I can work on the other ideas I have queued up.
- Did you remove the skill to summon gargoyle when spraying fire?
I did not actually implement that skill in the first place.
I am, however, planning on adapting a player-optimized version of that skill eventually—along with an Ordrak-style "sacrifice" skill, killing your gargoyles to restore health.
EDIT: Version 16 should now include both an "acid breath" skill adapted from the ghost-dragon boss, and a prototype "gargoyle spawn" skill adapted from the Vyrax boss. The summon needs retuning.