If you look at the fuse panel, there is a specific fuse that (when pulled) will disable the DRL feature. I did it for my truck, when my youngest son (who owned it at the time) was leaving for Travis AFB. Guards on the gates request that headlights be off when driving thru, and (as you know) DRL's don't turn off.
I think fuse number
20 is the right one, if my memory serves me right. Look at the fuse panel door and also in your owner's manual.
Nothing else is affected by the removal of that fuse.
As for the discoloration of the headlight lenses, you gotta couple options.
1. Buy a kit that has everything you need, plus the instructions, to clean and polish the lenses.
2. Buy a set of replacement lenses from a dealer, the aftermarket, or a salvage yard. Check out
www.latemodelresto.com and see what they have to offer. Also,
www.lmctrucks.com and
www.classicparts.com are two more sources.