I read his build and reread again. I didn't see that he opened it up and removed old insulation. I was planning on removing all insulation and tar from the wood and fridge cavity. Will that not be enough? That's why I was concerned about using this fridge after i seen that build. And this is why I'm on here to learn and ask for help. If wood frame isn't safe what should i do next? Thanks for you info.
Did you also read where he heated it up to 425 deg. The reason his burnt was he did not remove the old paper backed insulation and got it hot enough to ignite the paper. You should not have this problem cause you have learned from his mistake and are insuring that there is nothing flammable in the walls of your smoker yes the would is combustible but with the lack of air in the walls you would have to get the wood way hotter than you what you will ever get. This is another reason I would not fire this type of smoker with gas or charcoal, It has a wood frame and if your fire gets out of control it could spell disaster. I would go with a PID controlled electric burner for heat. With the proper insulation {like Roxul} I would feel comfortable taking your smoker into the 300 to 350 deg. range if I wanted to {and I never do} smoke something that hot.
Keep Smokin!!!
Wolf