I didn't have much luck with Hikari small bites-which is sorta the same thing. NLS is higher quality though.
You are going to HAVE to clean the bottom of the tank regardless. You don't want funk building up in there. You can reduce the power of your siphon by adjusting the height of the catch bucket. The closer the bucket it to the level of the fish tank the less power the siphon has. I promise they can take quite a bit up sucking up and squirting back.
I learned the hard way to keep the catch buckets clean. Rinse and disinfect with a vinegar rinse after use. It is a learning curve when learning good fish keeping for sure!
Live food is always going to be your best bet if you want maximum growth and the most survivors but I have been there and when first learning how to do it, live foods are a PITA. You really want to try as much non live food as you can at first but it really does get easy. Almost as easy as non live foods. After 3-4 spawns of slow growth and big losses you will see
For me personally, green GREEN water is the easiest for 3-4 days after hatching. It doesn't foul the water at all. Banana worms for 3 days after that only because they are slow and sorta just wiggle in place. BBS after that. I do one feeding a day of worms though. Mine seem to have swim bladder problems when fed nothing but BBS. Only a few but it still hurts my heart to watch them bounce off the glass because they can't swim right.
Just keep in mind where your fry are in relation to food. They stay very still and near the top for the first week so slow moving food that stays near the top feeds the most fish. They venture out more during the second week and will forage on the bottom but they are still slow and uncoordinated so food that hangs out at the bottom or very top and moves slow works well. Once they have the steering down better then you can give them whatever you want so they can catch it.