A few more things to look for:

Auto-close.

Auto-shrink.

Recovery Model.

Auto-Grow settings, very important if somehow databases got on to the C: partition.

System databases are getting backed up.

DBCCs and index maintenance. I run them as scheduled jobs, not through maintenance plans, so as to get more detailed output.

LICENSING. I'm concerned about the server licensing more than the client licensing.

When I started at my current job, the help desk ticketing DB was set to auto-close. And auto-shrink. On a dual P3/500 box. It wouldn't have been so bad if it hadn't been seven months ago. Funny, that server is now a lot more stable now that those two settings are turned off.... 😀