Here's a site if you don't know about it already. Aqadvisor.com basically you put in your filter/tank size info and select the fish you want in there and gives you a good estimate on how much water change a week and how many fish you can put in there. Of course it won't help for suitable tankmates and how they'll get along but it sure does help while sketching out a stocking list!
You could do lots of ghost shrimp, like 10-15 if you really wanted to! Shrimp have very tiny bio-load so you could pretty much have whatever you want (within reason)
But so far it looks fine, I believe most molly's get up to 5 inches and do best in Brackish water although some can thrive in freshwater.
As far as plants, some great low light and low maintenance plants are Anubias, Anacharis, some Crytocorne's, Java Ferns and java moss. I've had my Anubias's for a year now and have gone through a lot and I still haven't killed them yet lol
EDIT: also all of those fish you have there are mid-top level swimmers. I would scratch the Danios out (besides they are genetically colored, but it's fine if you want them), they like larger groups anyway and LOTS of swimming space. You should look into some small cory cats and get about 5-8 of them since they are mid-bottom level swimmers and like to scavenger everywhere.
Rembrandt II, Suiché
Leopards: 1:4 Hawkeye, Luna, Astrael, Dorian, Cullen
Gargoyle: Cloudjumper and Toothless