To safeguard yourself against MDB corruption, store as little dynamic information in Access as possible. I've got lookup tables for combo boxes in my current Access project, everything else is in the SQL side where a bulk of the work takes place.

Myself, as the developer I always kept a copy of the full MDB and the 'runtime' version in case someone mucked up their copy. In my current project, I'm working with a hosted server for the first time and am planning on setting up login scripts to always copy a fresh copy of the runtime Access DB to the user's desktop when they log in as I'll have some 100-200 users peak and don't want them all banging against the same copy of Access, so they each get their own.

I've had no problems with Express using batch files, SQL scripts, and OSQL/ISQL to do backups and DBCCs. Depending on the number of users on the system and how much back end processing is going on, you might need to be concerned about the 1 gig memory limit in Express.