Plumbing--need your help

[sharuq1]

What if I were to make a coast to coast inner overflow that is 2.5" across by 48". Then, because the holes are at different heights, divide it with a piece of glass down the middle, essentially making it into two overflows with the look of one?

Also the ball valves I was thinking of to put on there were mainly if I wanted to turn it all off for whatever reason.

I was thinking of teeing in a valve to one of the outputs that goes "nowhere" in case in the future I want to plug another tank into the system on the bottom (like an extra refugium or something?). Or would I be better off teeing that to the return pump instead just in case I don't put it on the bottom?

Does anyone know where I could find some flatter strainers to fit over the bulkheads to keep snails etc. from getting in?