eric, please do not be offended but you sure are having alots of issues with your truck. what year and how many miles do you have in it?
as for all the work your doing on your truck, i sure hope your garage is heated.
As for the coolant change, what i usually do it just flush drain it, and refill. let it run for abit with the resevior cap open and that usually takes care of my air problems. never had a problem with air doing it that way. i could be lucky though. also on top of the rad on the left side (if your looking from the front) is a bit plastic screw with slot. take that off when draining and refilling. whatever anti freeze you're using, make sure it's good for aluminum