1. SPD pedals on all bikes,

2. Multiple shoes; I have really sweaty feet, so I need to rotate shoes to ensure adequate drying time in between. I also fumigate my shoes with tinactin right after a ride, but that might be more detail than you're interested in...

I never noticed any problems with cleats being OK on one bike and not OK on a different bike, I align the cleats according to the one bike I ride the most.