Questions - Need some input

Has anyone ever tried this?? I know this is from a cichlid website but wonder how it would do in SW

http://www.cichlid-forum.com/articles/ug_jets.php

If you build your overflow in the center of your aquarium does it need to be made with the same thickness acrylic as the tank? The thickness calculator says that it will require 1/2" thick acrylic due to the pressure of the water on a 24" tall tank. I am trying to determine if I can use 1/4" or 3/8" thick for the overflow as I don't think there will be any pressure on it since it will be filled with water.

Any thoughts would be appreciated.

Can i use an Eheim 2217 for temporary filtration until i get my sump built?

We have a 90g aquarium at work that is more than 17 y/o that the silicone is showing it's age and has algae that has managed to grow between it and the glass in the corners. Can we use a razor blade to remove the old silicone and reseal the corners without compromising the structural integrity?

I am contemplating setting up one of my 55 gal to get the tank cycling while I am building my display tank stand. When it is ready then transfer the substrate, LR and water from the 55 into it.

Any thoughts on doing this?