RE: MUP or pseudo-bike paths... You have your head in the sand and are just plain, er, lacking thought, if you expect:

families to keep their kids regimented
dog walkers to keep their dogs on a short leash
lovers to walk single file
people to eschew the pleasures of listening to music

Folks, it just won't happen and you are being unreasonable to expect it. Ride your bike on those paths with the understanding that you are sharing with people who couldn't care less about your bike riding. Kids need to weave around when they cycle. Lovers need to hold hands. Many of us like listening to headphones. Dogs like to have 10' of lead rather than 2'.

Just my opinion, but I have plenty of rural roads to ride on, and that's where I go if I want to ride fast.