Thank you for your reply @dec.
As for comparing different collections, there is no way to do that directly in FontBase at the moment, although this does sound like an interesting idea and we will possibly consider it for implementation in the future 
As for renaming a collection - here is a quick guide we’ve posted a few years ago on how to do this:
The ability to rename collections has been present from the very moment collections were introduced in FontBase from what I remember.
Hope this helps.
Yuriy