Jess, you are right about chamber temps dropping when you toss in some meat, not only due to the thermal absorption taking place from the cold meat soaking up alot of heat at first, but from opening the chamber itself. It's a balancing act of sorts...once a large cut of meat goes in, chamber temps will not be stable for 1-2 hours with a lighter built smoker, as there's not much thermal mass to hold onto that heat. Then, as the thermal absoption rate of the meat slows down, chamber temps will begin to climb.
A method I use for propane and charcoal vertical smokers is to start with the meat loaded into a cold smoker (just added the initial bed of coals, or just lit the gas burner), then get the fire up to temp and watch for spikes until the meat's absoption rate drops off. It doesn't take long to get accustomed to this method is you understand the principle behind it, and usually within 2 hours, I have temps riding nice and smooth. It's probably not as easy for some folks to do it this way, but it works out fine for my smokers, and it only takes me 10 to 15 minutes to get the rig up to temp, and I have started with stable temps about 50* lower than where I want to run and just it climb into my target range on it's own...just some food for thought.
Yea, your hubby's not very knowledgable about hot smoking. 100-150* is considered cold smoking temps, which should only be used for cured meats in most cases. Without curing, 225* is the minimum standard temp for most cuts of meat when being cooked by a novice, and more experience smokers will at times opt for lower temps in certain cases for fish or smaller cuts of meat, depending on cross-sectional density, which will determine how quickly the exterior of the meat will heat through and be cooked safey without hovering in the danger zone for too long. Also, with enhanced (injected) or deboned cuts of pork or chickens, it needs to be cooked a bit faster than intact whole muscle meats would need to be cooked in order to be safe to eat. He obviously does not understand the safety aspects of low & slow cooking, so that said, keep doing it the way it works for you to cook it safely.
Keep your chin up and do what you know is right.