Am I Feeding Enough?

If you are feeding 2 or 3 times a day, that amounts to the same as one feed all gone in 30 secs. You could maybe increase a bit (maybe half as much again).

I wouldn't worry too much about the danios feeding on the bottom. My green neon tetras do and they're supposed to never go near the bottom. And one of my dwarf chain loaches has been known to feed at the surface - they are supposed to be bottom feeders.