Didn't read everything but thought I'd offer my opnions on the few that I saw.
Any of the Microrasboras like the Chili Rasbora make great, tiny schoalers.
Corydoras pygmaeous or hastatus make great tiny schoalers too. Contrary to being a Cory, they swim in the middle strata of the tank. If you wanted a tiny schooler for the lower strata, Corydoras habrosus would be your fish.
In my experience, CPDs or Endlers don't entirely school, its very loose. They will mostly be around each other, but the tight schooling behavior doesn't really exist.
Obviously cardinal or neon tetras school very very nicely. Beckford's Pencils probably get a little larger than you want and they can get testy with one another.
"What the world needs is more geniuses with humility, there are so few of us left."
Don't be afraid of predatory fish. Unless you are a small fish. Then be very afraid.