I like the idea of giving them a fair amount of land for them to walk around, but I think it is much wiser to give them that via 'above tank basking area' if you could pull something like in the pictures, but through a above tank basking area, that would be awesome!
I bet you would realy make some money if you sell custom made docks/above tank basking areas, some of us turtle owners arent that handy, and rely on already made products, but a lot of those already made products are made out of cheap material and tend to breakdown over time..an above tank basking area, or good sturdy turtle dock, is something a lot of us want. The benefit turtles get from these 'above tank basking areas' is more swimming space! This allows the keeper to fill the tank with water all the way! RES love deep water, so this is a plus.
Are your RES starting to get aggressive? I didnt understand 'are starting to you know what' if it's the fluttering, it is probably territorial. You can buy or make a tank divider instead of wasting all that swimming space.