I think you would be safer riding in the road or bike lane rather than sidewalks. The problem with sidewalks is that cars pulling out or turning into side streets, parking lots and driveways often don't look for (or expect) bikes on sidewalks. Drivers are focusing their attention on traffic approaching on the roads, not the sidewalks. Even if they see you, they usually will block your path when pulling out. A better approach is to ride on the roads or bike lanes and make yourself very visible with a good light system and brightly colored clothes.

There are reasons why bikes are generally not supposed to ride on sidewalks. In addition to the reasons listed above, you always have the danger of hitting pedestrians, runners, etc. Of course, there are always exceptions to the rule, and sometimes the sidewalk is safer than the road -- particularly on roads under construction or in some cases very narrow ones.