I do updates when suggested but I ignore the ads, especially the very tempting ones like "Your download is too slow"
uTorrent is excellent tho. I started with Azureus a long time ago and it has nice features but it is bloated and slow. Java based if I remember correctly. uTorrent is much more efficient especially if you pull stuff from Dime or TTD and leave them seeded for a long time like I do to help with ratio and to help others get old stuff.
foobar to listen on. I used Winamp for a while as well and I know many people like it but I felt it wasted a lot of time looking pretty which is something I don't care about. Foobar is great and seems especially well suited for listening to downloaded filesets. Right click and "Enqueue to Foobar", etc.
Lots of things can cause blue screens. Could be torrent client, could be winamp, could be something you downloaded, could be confused OS or driver issues. hard to say. What's the last thing you installed or changed prior to noticing that start?
If it's frequent you might consider reinstalling the OS fresh (ie wipe the drive after doing some REALLY good backups) especially if you've been running the box for a while.