Dunno about the magnets, but good questions on the skeg profile. It seems that all the glass boat manufactureres use the low profile that you describe. Lets throw another variable into the equation: placement along the keel line. Perhaps a small-profile skeg as far aft as possible might be the key to controlling weatherhelm, whereas a dagger-like skeg placed more amidships might be better to control slideslipping (like a center or dagger board on a sailboat). Any thoghts or theories about skeg shape/surface area/placement?