We get a lot of other-than-cyclists on our path (East Coast Greenway). Although we don't have any access roads to contend with like you do, we get a good amount of people (lots of moms with small kids in strollers and on-foot) whenever the weather is nice. Summer weekends, drop your speed to about 2mph, because anything can happen. I kind of enjoy the opportunity to see if I can control myself, though.
There seem to be a lot of different configurations for M.U.P's. If everybody would just take care and try to be reasonable and courteous, things would go well in all areas.