I don't see why were rats/wolves/ other neuri wouldn't be able to jump either. Since the npc ones can do it, it seems to make perfect sense. Technically, you would have the strength for such, so why not? Makes less sense to have to run through the church when in reality you would just jump up there and pummel the agressors against you. Maybe something small, like five to ten meters would be reasonable?
But I digress, sorry for getting off topic.
As far as skins go, rdd, given the game engine alots for only red dragons, the question also remains, if you were from another dragon background, could it be lettoed for the proper resistance and wing type/tail type amongst other things?
There is a handy thing which is in the eberon world, soft leather gloves which allow half dragons to appear as thier other self, ie, elf, human, dwarf, ect. It is possible that some of the mages (npcs) would know of such a thing and possibly make it available to players with the class. This would solve any issues with appearance, though I imagine that it would be more of a description on the gloves and a rp tool, unless you could take them off and polymorph some how. But I think that might make things too complicated.