Although Florida allows sidewalk cycling, we are mostly responsible for any collisions with a pedestrian. A local lawyer who is a keen cyclist himself, recently brought up the issue of electric bikes on sidewalks. There is no law against it but if a rider is tempted to hit 25 mph on it, it could lead to a serious crash. Most of the sidewalks in this county are not fit for fast riding, though, because they are old and not well-maintained; okay for pedestrians, though, but very few people walk on them.
I was riding on a bike lane a couple of years ago. I use my bike mirror but I can't see everything in dense traffic. Suddenly a huge mirror on a pickup truck whistled past my ear, just inches from me. A second later, that truck took up the whole bike lane, then he suddenly realized where he was and swerved back on the proper driving lane; had he done that a second earlier, I would have been hit by his truck. Even the bike lanes are dangerous. We have flashing signs above the road, warning drivers to put the phone down; too many drivers are looking at phones, which is why the sidewalks are safer. I've ridden them for five years and had no problems.
One thing I have to watch for is when I'm riding the sidewalk against the flow of traffic. A driver pulling out from a side road is looking to his left for oncoming traffic, and won't be looking to his right to see a bike coming. There was a fatality a couple of years ago when a driver suddenly hit the gas and pulled out as a cyclist was about to pass. I, myself, almost hit a cyclist in that manner when I drove my van out of a side road.
It's time that Los Angeles (and other places) look into this matter of sidewalk riding. Around here, there are numerous memorial signs where cyclists were killed. Roads with two or three lanes in each direction is no place for a bike. And speed limit signs don't mean anything to drivers.