About the input jack... Take the jack plate off and tighten it as tight as you can get it... I also use Loctite on my strats. It's a paste like stuff that is often used in the automotive industry and other mechanical devices to keep lug nuts and bolts from loosening. Dab a little of it on the threads of the jack and thread the bolt in... then carefully wipe the excess off. Once the stuff drys your jack won't loosen unless you take a screwdriver and break the stuff loose. It works good. Strats are pretty well known for that because of the way the jackplate is... this little trick will fix it up.

As for the strings... you probably have oily fingers... which isn't a bad thing or anything... it's just bad for your strings. Get some stuff called Fret Ease or Fast Fret... they will clean your strings and lubricate them so it's easier to play... I think Fret Ease also conditions your fretboard... anyway, it's good stuff and will make your strings lat longer. I personally can play the same strings forever (i use ernie ball and GHS) and not get rus spots or anything on them... I guess I'm lucky.

Good luck with it though.