Adding/customizing items

When adding several items from a list, I would like to do some action with all the selected items - especially when it comes to tags. When picking 10 books of a list of Pratchett-books I want to tag them all with "[Fantasy]" at once instead of having to tag item for item by the "add tag" in each items overview.

Would increase usability.

Furthermore it would be nice if I could select my own tags from a drop-down list - avoids having similar tags with different names.

Good ideas, will be implementing these.