Re: Peer review template 
It appears that many featured articles also feature in Category:Old requests for peer review, which indicates that most people haven't removed the archived peer review template from the article's talk page even after it had achieved Featured Article status. However, I can't really comment as to whether the box should be removed; I'd suggest posting a message on either the peer review talk page or at the village pump if you want opinions from more experienced editors than myself! -D