Well, I think you have answered why those places were removed, basically. The drawbacks you have posted were either meaningless (DC loss, time limitations), or so harsh the only way anybody would do them is by doing non-interactive I'm-just-a-tinker-bitch characters (perm stat/HP loss). XP loss falls into the later category, maybe not obviously. But.. level up the tinker bitch, get the necessary skills, and then who cares about the tinker bitch losing XP, once you have the skills?

I have yet to see a good reason WHY some places should give special abilities to forged stuff. It really doesn't add anything except imbalance.