On the rust thing, I have a potential solution. If I get sliders, I intend to "paint" the entire surface of the body underneath the sliders with plasti-dip. The goal is to create a barrier of rubber between the slider and the body. I've seen people use gaskets, but water can still get under a gasket, especially with freeze/thaw. Water should not be able to get under the plastic-dip.
Again, this is just a theory. I haven't seen anyone try it but I think it would work.
