Hi there, in semi-response to your question #2. If you know what the program is called / the command to execute it, you can find which one is being called when you try to execute it. For example, if you installed the "Winamp for Linux", called xmms, you would go:
That would give you a directory where your xmms executable is running from.
Also, when querying RPMs, I don't think you use the .rpm extension, I could be wrong, but that might be why it said "not installed".
Hope that helps a bit.