Search results depend entirely on the responder, not the software you use.
Limewire is the servent most guilty of returning partial matches to searches.
BearShare deliberately errs in your favour and shows all results, though you can
restrict it a bit in Setup/Searching by selecting "Hide non-matching results".

Shares will not appear until you have downloaded and shared them, and are
not supposed to be filled with your own searches. If you are sharing nothing,
wouldn't you want the software to be aware of that? Simply put; if you aren't
actually downloading and don't have the files yet, how can you share them?

Feel free to share more folders whenever you wish from any disk on your
computer. The downloads folder is only one option, and obviously you aren't
being "forced" to share it if you were able to unshare it so easily within
minutes of installing BearShare. It is selected by default as a convenience to
users, nothing more, and there is nothing sinister about that.