3. Too advanced? Maybe for the first few minutes, but Avast is simple, really.
4. If you're using this for non-commercial use, Avast Home Edition is free (It has everything but an Enhanced UI, script scanning on pages, PUSH updates, and a couple other things).
If you're using this for commercial/etc. use, then I'd try out some other apps as well. For free, Avast is spectacular. Check out sites like PCMagazine and CNET before buying security software, though.