get more neons and some more white clouds so they can school better. as for the snails, i would have resorted to fish warfare as a last measure but here are some ways to keep snail population down:
1. use the bait and hook technique. get some veggies like cucumbers, zuchinni, romaine lettuce, etc and blanch (boil or nuke) them for a minute or two so they are edible to the snails. tie the veggies to a string and sink them. after a couple of hours or overnight, there should be snails all over it. fish them out, discard and repeat if necessary.
2. snails often flourish because of extra food. unless you are purposely feeding them, you are probably over feeding your fish a little. cut back on the sinking waste like extra flakes and whatnot during feeding. your fish won't be negatively affected and your tank will be cleaner in terms of organic waste. less extra food there is, the smaller the snail population will be.