It's about how you do it
Not what you do. I do it all: ride on sidewalks, run red lights, cut off cars, get too close to pedestrians. Have never once had any problems with cops, drivers, or other people who aren't on bikes. The only enemy of my forward progress are other cyclists, who all seem to think they're in a position of authority on how I ride. It's all about how you conduct yourself. If you're stable, respectful, and don't put anyone in danger, nobody will care what you do. Except other cyclists because they're the worst.