I find never-seize on threads to work magic minimizing corrosion, but
one has to be very careful not to get it on the phillips head or the
phillips driver. Even traces of it (or paint) make the drivers cam
out. Buy lots of spare screws and drive bits. Use solvent on the
drivers and the screw heads.

It doesn't help that those damn AN structural screws (can't remember
the number) are so soft and the phillips socket so shallow that the
heads strip out much easier than those unapproved pan head stainless
fasteners. I don't know what they offer except of course a full
diameter shank and a lot of ductility.

Some of you must live in a very corrosive environment though.