Depends on the type of path. Particularly within (parks in) cities you can find paths that are destined for pedestrians only. But then there are MUPs (Multi Use Paths) too, which are open for all.
No - it's illegal
Yes, the Amish people can and do ride bikes all the time.
Yes, many people ride bikes.
No
Practice....
Because it's awesome. I ride mountain bikes competitively; however, dirt bikes add an extra dimension of fun.entertainment. people ride because its fun to do. it can also be for compitition, or even transportation.
Because it's fun!
yes
Ride Bikes Ride Bikes
They play baseball or ride bikes.
only if he or she wants too
Wherever they wanted, could, and were allowed to.