Your save worked fine here, as long as I avoided running the mouse cursor over any containers (dropped loot appeared to be ok); mousing over a chest or cabinet, etc causes a crash, so I assume hitting the alt key near one would as well.
I moved around by clicking on the mini-map, and control-clicked to attack (less mouse movement minimizes the chance of hitting a container). I didn't get to the third level, so I'm not sure if any quest items lying on the ground there would also be a problem.
For your girlfriend's save, if you are going to try replacing the inventory files rather than deal with any other missing items if and when they crop up, it would probably be safer to start clean than use my set. My inventory from an act 1 save prevents your save from crashing in the BF, but equipment still gets corrupt. If you decide a replacement inventory set is required, you should make a copy of your save at the end of act 1 (ie where you are now), replace the inventory files with those from a new game, reload, head up the stairs to enter act 2, save and use those inventory files.