ive had a female Betta in my community tank with two Platies five Mollies four Cories Singapore and Amano shrimp and a Plec and there has been no confrontation. when i was at the lfs i watched the tank full of females for a while and noticed my female was very calm, bought her and she hasnt changed. the other fish dont bother her and she doesnt bother them, she swims around my rocks and in the cave most of the time but sometimes swims with the others.
females are more placid generally but i wouldnt give an outright no to saying a male wouldnt be suitable with your fish, ive seen many tanks where its been successful, really depends on the temperment of the Betta.
Betta and Tetras are a no go though, they treat them as lunch
Nick