If you are removing tartarians you might want to remove Wish, Although I would be against taking out tartarians.
Someone has a mod out there that enhances the reward of the Arena. Its minor but makes the Arena at least sometimes worthwhile, which would be nice.
Maybe include the flags mod for the better visual effects?
Maybe leave fever fetish but take out the other two gem generators? Otherwise Machaka=
or you could change the required forging level to make them harder to use, perhaps 4 for fetish and 6 for clams and stones? Also I've always thought making artifacts require construction 9 was a pretty good idea.