Suggestion - Tag a bunch of stuff at once

Maybe this has already been suggested. Maybe this already exists, and I can't figure out how to do it. If either of those are the case, let me know how dumb I am.

If I'm not stupid, I would very much like there to be a way to tag multiple things at once. If I search my collection for say, Mario games, I would like to be able to apply the mario tag or the Nintendo tag to ever one of those items at once. I should select all their checkboxes and then add the tag to all of them. Having to do it separately for each item is annoying.

Another thing that would be nice. There are quite a few items, especially books and DVDs, which have volumes or sequels. Is there a way to get them to automatically copy the tag from their predecessors? Let's say I buy the first season of a TV show on DVD and I put a few tags on it. When I buy season 2, it should just inherit the tags from season 1. Same goes for books in series or game sequels, etc.

One more. Maybe there would be a way to see the most popular tags for an item and add them by clicking on them without having to type them in.

Thanks.