Now, why wouldn't you just keep the bottom element in place, lower a rack to sit on in and use the pan to have the chips smoke? No need to cut a hole now... Unless for some reason the element would cause an arc?
If you go with the gas way how's about this? remove all the bad/melting stuff and get a bbq burner and hose and place it in the drawer. All you would need to do there is cut and protect a small hole for the gas line to run out. The the whole base of the inside would get warm and if you drilled a few holes in the base it would then allow for more heat to get through. The base would act as a drip pan as well as your bowl for the chips. As long as you don't have the chips sitting over a heat hole then there shold be no fire in the main chamber. I'm just thinking here of ways to do it and it may not work at all... just saying...