1) Be glad you live in Seattle and you actually have MUP's to ride on.
2) People get angry for all sorts of reasons. Especially in cars.
3) I wouldn't do anything any different, except maybe dismount at the intersection between 3 and 4 and walk it across. Just feels a bit wrong to do pedestrian stuff while on wheels while cars are coming. On a sidewalk, going slow and being very *very* careful, since drivers don't know what you're going to do even if they see you.