There's a sticky at the top explaining the tags. I'd suggest [Features] or [Site Behaviour]. Don't worry though, no one will get upset if you use the wrong one. I've made a ton of suggestions there in the last few days. :)

I think the reposting thing is just to maintain the quality of the site. TBH, if you have a case for changing it, post the suggestion and let the community vote on it and see what the admins' approach is. I do think, though, that a functional solution to xposting or similar is superior to duplication of the snap.