I think that members being able to kick obnoxious or harassing people out is a good idea. That said, with the "don't do [list of things] focus of the rest of this policy, I think that this clause invites rules-lawyering. (aka "You need to leave." "Nuh uh, I didn't actually violate the policy!" as the second person trades on technicalities.) 

Alternate wording options: "Any NIL member may expel another member or guest for failure to uphold the code of conduct/violation of this policy/failure to behave in a respectful manner/(whatever your goal is)." 

It is also best to be careful about writing in consequences if you are not sure they will be enforced. What happens if key community members are the ones violating the policy? CWG members? Will they be asked to leave, or will that be too awkward? An un-enforced zero-tolerance policy may be worse than a nonexistent one. See Readercon 2012 (http://geekfeminism.wikia.com/wiki/Ren%C3%A9_and_Readercon) for a spectacular example of this.