Excess silicone is nothing new, I've seen lots of tanks that have some extra at the seems. It doesn't seem to bother anything.
What I was saying about the glass, is that the side pieces of glass are sandwiched in between the front and back pieces, so that all the exposed vertical seems on the tank are facing left and right from the tank. I've always covered up the sides with paper and tape and the top with a towel to keep paint going where I didn't want it to go, but that was mainly for aesthetic reasons.