Dragon Monster Class - WIP

[Loxsis]

I'm working on making a PC-friendly way to play a dragon in FFd20. I have Dreamscarred Press' True Dragon Monster Class for reference, so I guess it's more of a conversion. Any suggestions would be greatly appreciated.

[Loxsis]

Base Stats:

Hit Die: d12 (full BAB)
Good Saves: Fortitude, Reflex, and Will
Class Skills: Appraise, Bluff, Climb, Craft, Diplomacy, Fly, Heal, Intimidate, Knowledge (all), Linguistics, Perception, Sense Motive, Spellcraft, Stealth, Survival, Swim, and Use Magic Device
Skill Ranks per Level: 6 + Int modifier (minimum 1)
Weapon Proficiency: Simple weapons
Armor Proficiency: None

Limit Breaks:
Mighty Breath (Su): Use a special Breath Weapon that deals double damage and twice the size of your normal breath weapon. If you don't already have a breath weapon, you use a breath weapon as though you were 2nd level.
Elemental Aura (Su): emit an aura that deals damage equal to your breath weapon within your bite's reach for 1 round + 1 round for every 4 levels after 1st. You cannot absorb damage from this ability. If you are 1st level, this aura deals 1d6-1 points of your element's damage.

I'm planning on having dragons having immunity to their element, half damage of their element's strength, and vulnerability to their element's weakness at start, gaining absorption of their element at 10th level and immunity to their element's strength at 20th. I'm going to have 5 size increases spread out, with the final one at 20th level, and 6/9 or full spellcasting.

What are your thoughts on 1st level fly speed?