Nice!
I've ran water through glued pipes and with in 10 minutes.how long do i have to give the cement before i can run water through it? just curious, probably won't happen for another few days.
I thought you might need to frame around the opening instead of having the frame hanging there. But I have not done this myself before. It just look unfinished to me.
Do not use silicone to stop the leak. The gasket should stop the leak. You might need a new gasket or it's not tightened enough.
If I were you I would move the sump out of the stand. And build a removable platform on top of so you can work on the tank.