Thor is so cute- you have to add more pictures!! Sounds like you are doing all of the right things so far. My only suggestions to you would be to not pull a treat out and put it between the two dogs ESPECIALLY if you are doing this after Thor has already started to act up, and displaying some of the behavior that you are not comfortable with. The reason behind this is Thor is inadvertantly being rewarded for his misbehavior, he may soon realize that if he acts up, gives a growl or snap or two, Mommy will give him a treat!! The other advise you have been given is great- I used to have the same sort of problems with Hutch, but then I realized it wasn't Hutch with the problem, it was me. I was anticipating his reaction, and he could feel me tense up triggering his nuisance behaviors. Once I learned how to react properly, he just followed my lead.