Awesome setup dude. Can't wait to see it filling up
As for the rail, well, I'm a bit wishy-washy about it. Besides having to put it back later, you're going to get all kinds of paw prints on the tank when peeps go downstairs.
But on the plus side they can still use the other railing for support.
I think once you close the sump area up no-one will care about the rail being there and I want to agree with you leaving it intact