Only come across one or two beach cities in the south bay area that prohibits sidewalk riding, usually near the ocean where there is very little room for even peds to walk side-by-side but there is usually a bike lane provided in those areas. Its a safety issue with me whether or not to use the sidewalk or not and lowering my speed accordingly to cruising/jogging speed. Some streets are too narrow and car density/speeds too high at certain time periods for my comfort level.
As far as night riding, many police depts will stop you now if only to warn you to add front and rear lights. Reflectors arent enough anyways. Wear a reflective safety vest (orange is best all around than the lime ones) if I am on an extended night ride or know I will be riding in the dark for more than an hour. Added custom/home made cut reflective tape on my helmet (on the crossmembers) so my visibility goes up because the pattern is unusual and drivers actually slow down and some hit their high beams to see what it is...lol. Amber reflectors are more effectively seen at distance than the red ones. Someone stole my rear red one and I used the white one I had laying around out back and that worked out wonderfully. Found one of those "bling auto letters" that fell off in the street and hung it from my saddle and that caught the attention of motorists because it sparkles like a diamond in light.
As long as you arent riding crazy or blowing thru signals/stop signs, the police will generally leave you alone...night or day.