If the bootstrap loader gets corrupted or erased, is there a way to reload it into the flash ROM?
The bootstrap loader is stored in bank 0 (the first 64Kb) of the flash ROM. The loader does not give you a way to zero out that bank, or to load anything into it. Thus, it should be fairly safe from corruption or overwriting.
If by some weird chance the bootstrap loader in the flash ROM gets clobbered, then your only option is to send the board back to Dallas Semiconductor to have it re-flashed. Dallas has announced plans to burn the loader into ROM within a future version of the CPU, making it "permanent" and avoiding the small possibility of a problem that currently exists.