I agree with everything the others have said.
Be aware that some dogs inhale their food naturally. Does he throw up after every meal, or very often? If it's just an occasional thing I wouldn't worry...
To slow a dog down + help with the resource guarding, feed him a piece at a time. Make it a game sometimes, he sits, he gets food. He downs, he gets food....make it fun!
Also some people scatter kibble on the floor, or put LARGE rocks or balls (make sure they're way too big for him to get into his mouth) in his bowl so he has to eat "around" them.
To help get him relaxed around eating & high value chewies, this is a good link:
http://www.ahimsadogtraining.com/han...-guarding.html