Regarding #3: In Seattle it is legal to ride on the sidewalk.

Section 11.44.120 RIDING ON A SIDEWALK OR PUBLIC PATH. Every person operating a bicycle upon any sidewalk or public path shall operate the same in a careful and prudent manner and a rate of speed no greater than is reasonable and proper under the conditions existing at the point of operation, taking into account the amount and character of pedestrian traffic, grade and width of sidewalk or public path, and condition of surface, and shall obey all traffic control devices. Every person operating a bicycle upon a sidewalk or public path shall yield the right-of-way to any pedestrian thereon, and shall give an audible signal before overtaking and passing any pedestrian.

http://www.seattle.gov/transportation/bikecode.htm

Regarding #4: Very mature.