Lots of questions!
The best place to start looking for answers is LW's Help Menu, as you already know.

Re the uploads/hits, not all files that get hits are uploaded from you, for the same reason that you don't download every file that shows up in your searches.

Your friend can more easily find your files IF you are connected to common hosts in the Connections Pane. If you both enter each other's IP numbers in the entry box at the bottom of the Connections Pane, that can sometimes help. After all, not everyone can directly connect to everyone else at the same time!

Cheers