I've googled a lot but can't really find any great solution.

I've used the MSCMOD (that is available here on MTS) to get sims to lots and it works great. Problem is that it only works for bars and nightclubs and I can't seem to find anything like it for regular community lots. Does anyone know any mod or a way to tweak the game to get more sims on community lots?

Have you tried Shimrod's Townies Out On The Town. There are also links to a few other mods At The Bottom Of This Page. If you are using Story Progression there is an option to Push sims out day/night.