Auto body repair & detailing: shaving handles, filler panel, thin piece

Question
Hi, i have a 02 sonoma and im in the process of shaving the tailgate and the third brake light. as far as the tailgate goes i have it prepped for the relocator and the outside is sanded down to bare metal in the handle hole and feathered out about 2-3 inches around the handle itself.  what my question is, im to the point of putting on the filler panel and i know about welding it it but i have little access to a welder, ok welding skill nothing to brag on, and i've seen several people ruin a good tailgate by getting it to hot and warping the whole thing. Ive also heard of people glueing the panels in with a heavy duty 3m seam sealer. Would it be better to weld or glue it? I have 2years of vocational auto body and worked on paint side of a high production body shop for 2 years. I havent been doing it though for the last 2 years and i just wasnt sure. But any input would be great and i'd also like to do the same on the 3rd brake light, which as the tailgate really large thin piece of metal(scared of warping it) but thanks for your time. Just a young body guy trying to get some input from someone thats been around the block.

Answer
Hello again Jon! I was wondering how your patches you glued over your handle and third light turned out. Bill