Don't worry about matching fish that require the same water parameters unless you want to choose fish that match your tapwaters paramaters. Most people run their tanks with whatever their tapwater comes out anyway, and most fish can acclimate to that. Some more sensitive species don't acclimate well to water outside of their natural range, and many won't breed unless they're in the correct water, but otherwise should be fine.
All the fish in your tank besides the mollies have similar natural water parameters anyway. Guppies can live in almost anything, they're not an issue.
Danios can handle a wide range as well.
Your tetras naturally come from soft, acidic water, but unless you're planning on trying to change your water to suit them (which I don't recommend without plenty of research) this is irrelevent. Most people do much more harm trying to change their water to a different pH or hardness than just leaving it alone. Fish would much rather have stability than large pH swings while someone is trying to change the water to suit them.
Angelfish MIGHT prey on your neons once they reach full size, especially if your neons are pretty small. Put angelfish with caution, though they will likely be ok. My angelfish will chase down and kill any fish small enough, but neons are pretty fast.
You shouldn't have any problems with dwarf cichlids like apistogrammas should you choose to get some. There are a lot of very colorful species.