My scan turned up 85 threats; most medium, a few low. Now what? Do I select "fix" for all? Are there some that shouldn't be fixed?
Well,if you're feeling uncertain about clicking fix all,what you could do is look through the list.
If some are listed as tracks when you click on them,you could read about tracks,and decide if you want to fix them or not:
http://www.safer-networking.org/faq/usage-tracks/
Then,glance through,and see if anything is something you want to keep or not.For a quick example,you might use an adware supported program or something like that,that you're okay about using,despite the ads,so you'd rather keep it.
Uncheck anything you decide you want to keep.
That's addressed in number 6 here,too:
http://www.safer-networking.org/support/first-steps-tutorial/
Almost everything removed by Spybot is backed up into quarantine,so almost everything should be recoverable.
Hope that helps. :)