Hmm ok so far i have noticed that buildings on tribe lands can be effected only by the person who started the template this is going to create a problem eventually.

As tribes who build early and than grow are going to be stuck with a small town being unable to destroy and build anew, also not sure if it is going to be implemented but it would be great to help build by putting the materials in even if you yourself depending on your craft skill can't actually build it.

On another note this could turn into griefing on release due to the fact all they would have to do is join the tribe and build than leave and the tribe would be stuck with what ever the griefer built to hinder them.