This is a bit of a proof of principle.
It strips out all of the character classes and replaces them with a single interface screen (you can still select your class, but it is purely cosmetic,) where you buy an initial inventory, skills and attributes. I added a few mutations as well on a lark.
The prices for items are mostly the gold costs from shopping.cc (with a few modifications,) the prices for everything else are set so that you can generate a wizard, fighter or priest more or less as they exist in the base game (I think this makes religion too expensive.)
Obviously this means that custom characters will be, all else being equal, somewhat more powerful as they'd be min-maxed to one degree or another, so purists might prefer to lower the available number of points.
Feed back is appreciated; although this patch is perfectly playable this is more meant to stimulate discussion.
A diff is attached - I put all the changes in newgame.cc although some of them should probably have gone elsewhere.