I didn't read this entire thread so I don't know if this has been mentioned yet, but I wanted to make a suggestion in here:).
An adult dragon is HUGE. Does it seem likely that even the most decayed, inept Zombie could miss an ****** that is as big asthe broad side of a barn? How could a dragon possibly evade? It can't. I think adult (and ancient) dragons should have a big fat ZERO evasion skill (physical attacks, not magic. Magic is different, cause you aren't simply trying to jump out of the way).
Because they should have 0 evasion, they should have MASSIVEinate resistances against pretty much everything. Dragons should be easy to hit, hard to damage. In particular they should be resistant against:
Fire damage
Physical attacks (ranged and melee)
Energy damage
To me this makes sense. I shutter every time I see a 100 ton dragon tip-toe out of the way of an arrow:P. It is silly and needs to change. I know there are probably more important things about the game to change, but I think this could be used as a way to adjust dragons to make them more to their players liking.