Few random questions...91 Jimmy

Questions with pictures, everyone's favorite, here we go

1991 Jimmy 4x4, 4.3L V6


Here's my oil cap...as you can see something has been eating away at it, or it has begun to melt? I also noticed a yellow substanceabout 2 months ago when i was changing the oil, any idea what that could be?
http://img457.imageshack.us/img457/596/10011737sb.th.jpg (http://img457.imageshack.us/my.php?image=10011737sb.jpg)

The oil dipstick...Since the truck was bought a year and a half ago, the dipstick was attached to the oil cap with tie wraps. I cut them off today to make it look better, and i noticed the dipstick wasn't in the stock position. It's very loose, and has either been horribly bent, or was placed around a different section of the header. Top blue circle shows where the bottom one should be....are these hard to replace?
http://img478.imageshack.us/img478/7070/10011742fv.th.jpg (http://img478.imageshack.us/my.php?image=10011742fv.jpg)

Next is a rust problem...just wondering if there is an easy way to tackle it without interferring with the windshield
http://img460.imageshack.us/img460/6341/10011635ox.th.jpg (http://img460.imageshack.us/my.php?image=10011635ox.jpg)



They're just minor problems...but i'm trying to get the truck ready to sell