Rummynose Tetras like to be in groups of at least five. If your Bronze Catfish is a Cory, he'd appreciate a few buddies, as well. If I remember correctly, USD Cats like to be in groups of at least three or four, but double check that.
Neons and Angels can sometimes be kept together, especially if the Angel has been with Neons since it was little. In the wild, Neons are Angel food.
Whether or not you'll be able to "properly" keep more fish in there depends on how much filtration you have, how often you do water changes, and other such things.
You ought to be able to get a few livebearers in there, some Neons, or maybe an Angel (or two?).
I just got an adorable little Angel tonight

I'll have to take pictures of him tomorrow
Edited to add: Just saw your new post, Mariah. Mollies prefer salt in their water, so you'd be better off not adding Mollies. As a general rule, catfish don't do well with salt. Platies, Guppies, or Swordtails should be fine. There isn't a set number of how many more fish you'll be able to put in there. As I mentioned above, the number of fish you can add depends on filtration, frequency of water changes, etc.
Pamela
aka Married Lizard
