Should you marinade steaks with salt?

No, the idea of a marinade is to infuse the meat with flavor. If you then cook it in the marinade, it will be too strong a taste. Plus, it'll boil, making it pretty tough. The exception would be braising, which is slow-cooking at a low temperature in either wine, stock, tomato sauce, or combinations of them, with some chopped aromatic vegetables and herbs. In that case, you simply brown the meat (some don't) and put into the liquid to cook. Technically, this is cooking it in a marinade.