The molly and danios are not suited for life in a 10gal, really need at least a 15gal long and need to be in much larger groups, so you should rehome them as you tank is not suitabel for them. Rummynose and neon tetras are shoaling fish so should be in groups of 5-6 or more, i would get 2 more rummynoses and 2 more neons once you've rehomed the molly and danio's (which i would presonally advise as the tank isn't large enough for them).
I would advise keeping an eye on the betta though as tetras like neons have been known to nip the fins of betta's.