Wampus, I don't think one can register "independent" in SC. He can vote in either or both party primaries, can't he, if they are not held on the same day? If one does not vote in a primary, he is an "unaffiliated voter" and can vote in the general election thereafter.
Yes, you do have that option to register as an independent voter, semantics and terminology aside. (Independent is a term a nationwide audience would understand best, right?) Any registered voter can vote in the general election. Otherwise, correct.
The board of registration is a few blocks from me. I need to drop by and pick up some forms. Lots of work to do...