yeah... what he said

. When you wire anything aftermarket, I know its ugly under the hood, but have all the add-ons get their power directly from the battery instead of tieing into the fusebox or something. A couple of people have posted threads on adding MP3 players or radar detectors and wiring them to an existing circuit in the cab... bad idea when it comes time to warranty an electrical issue. If its on its own circuit directly to the battery then you can easily illiminate this when you are troubleshooting a problem.
Lifting is a whole other ball game. I would say probably not a good idea for your power train warranty (what I feel is the most important part). Obviously, right away all of your suspension components would be voided from warranty. If you ever had any differential/drive shaft issues, possibly even motor issues (especially if you go with oversized wheels/tires) they might try to blame it on the lift.
If you are looking at lifts, go with the CST for now. They have great kits out, kind of expensive, but they allow you to RETURN your truck to STOCK! which is very valueable, at least to me.