How can I keep my chain from falling off the inner chainring? (specifically, from getting stuck in the bottom bracket)
There is a bottom limiter screw on the front derailleur which may be of some help. Tension it up till it just goes far enough to shift. It's also possible that your rear derailleur isn't taking up the chain slack properly and is letting it bounce as you go over bumps. This would cause the bottom of the chain to slap as it goes forward to the front ring and could cause it to come off. In that case you might see about replacing the rear derailleur with one on which the tension springs are newer and reduce the slap.