I think you have some good points in there. I agree that in general i dont like the idea of enforcement as the best solution. Rather good civic planning can make many of these problems go away.

I certainly am physically able to ride around cars etc. But if we want the cities of america to evolve in terms of density etc then we need infrastructure designed so that a grandma on a tricycle feels comfortable enough riding to the store instead of taking a taxi. Its certainly done in other countries.