Thanks for your input folx.
T4B: The clips do not cut into the metal at all, because i didnt actually clip it on at all as its length would not fit the position of the hole. It's simply being used as a nut. Not clipped on to the metal or scratching thru the paint. Yes the clip is parkerized or has some such treatment, but never seen one of those types of clips rust ever. I worry about its interaction with the surrounding metal and screw is all.
Prolly being paranoid, but I think I'll remove it, coat it and the surrounding area in a touch of zinc rust stopper stuff, then wrap both sides of the clip in gorilla tape and re-affix. That *should* allay my fears.