Gorm, wouldn't that put a lot of strain on the point at which the pipe is connected? I think you have to spread the load a bit more than that.
Honestly, I think cleaning the brace is easier than cleaning the disaster that would follow a broken tank!
Is the problem that salt spray covers the brace and blocks light?
Actually when I bought my (overpriced) Oceanic RR 58G, I was contemplating the cheaper (by $50-$100) AGA RR 60G tank...but the AGA had a center brace so I spent the extra dough on the Oceanic.
My tall 37G (Yuck) freshwater tank has a black plastic brace and I know it's a pain when I'm cleaning the tank to have to work around the brace. BTW the tall 37G tanks suck, unless you have extra long arms.
If you do remove the original brace for one that is less obtrusive, I would suggest that if you can't do rim bracing all the way around, then at least try to do it on the long sides (front and back). A horizontally placed piece of glass or acrylic will resist bending in the direction of it's plane. (like how you can bend a plastic ruler easily in one direction, but not the other)
Good luck with whatever you do, and of course, take pics and put them in the DIY section!
V