I'm sorry, but I'm going to start off by saying please rehome your angel or upgrade your tank. Angels can get big and aggressive, especially in such small space. Angels need at the very minimum a 30 gallon aquarium; but a 40-55 gallon tank is ideal.
Mollies can be aggressive for many reasons. My old dalmation molly used to be quite aggressive.
Male livebearers are very.. obnoxious. I had two male platys, 1 male swordtail, a female platy, 2 female swordtails, and the main fish my molly picked on were the males. Especially the platys. Those two boys would never leave her alone.
Male livebearers tend to be very pushy with the females, which is why the molly may be aggressive towards him.
Also, mollies are little pigs. If she's aggressive at feeding time, that's normal.
But the main problem is space. Those fish really need a bigger tank. Please look into investing a 40 or 55 gallon tank and that should solve your problems
But your molly may just be aggressive by nature. Mollies are known for that.
My molly even used to chase around my big 4" parrotfish! Haha.