1- ride on MUPs as infrequently as possible. Ride roads instead.
2- you don't just pass walkers/runners on MUPs. You pass other cyclists too. And many times these others are 2 wide so letting them know you are there is a good thing.
3- bikes yield to walkers/runners on MUPs. Let them know you are there for safety then move around them in a safe manner. If you want to ride fast, see #1.
4- my God, this place.