Hi,
This is all possible.
For your first two questions - if you highlight a track in your collection, and look at the top of the collection list where it says how many tracks are in your collection. If there's a little down arrow, it means that track is in a playlist. If not, it's not. Click the down arrow to see all the playlists that track appears in.
For your missing tracks question... Click File > Display All Missing Files... This will list all missing and give you the option to relocate. (I'm on a Mac but pretty sure PC would be exactly the same.)