So maybe its me your video when you went to really low seemed fine I have a Silver C its not like low to high is a flamethrower. IMO cook on the damn thing not sure what you are cooking really low unless you are warming up stuff or keeping it warm and that would be easy on that grill use 2 burners to cook leave 2 burners off move what you want to keep warm to the side the burners are off. Its not a smoker so don't expect those kind of results.I drilled the side burners out to a size smaller. I tried them in there.. same thing.. just a smaller flame
You are confusing mixture with flow. Mixture can be off no matter what. It was fine. Just flowing too much gas at first glance IMO.I didn't see an real yellow tips on the flames, just occassional ones. I think it is probably burning about right.