This is certainly a very weird request. What if people abuse a certain tag, for example, posts that have nothing to do with bitcoin being tagged with bitcoin. It would be nice to have someone able to remove said post.
I undertand you're probably trying to avoid the /r/bitcoin censorship, but I see no reason why you can't just not use your "powers". They mighty come handy one day, for removing spam.
RE: Would it be possible to remove moderation permissions?