[Ayoka]

As for the snatching I would do different things about it in different situations...

Bear is generally avery soft mouthed dog. The corner store near where we used to live had treats for the dogs and all the staff there commenbted on how "nicely" bear took his treat and how grabby other dogs were...

Well he DOES get grabby when he's either starving OR VERY excited (agility class/Flyball)

We have worked on the leave it/off command (as Canadian Rottie suggested) and now he only needs to be reminded once that if he doesn't calm down and take treats gently this we generally use in obedience class where I am not coordinated enough handle a toy a clicker and a dog...BUT I have to say that in Flyball where we WANT him excited for his runbacks, I use a 3 foot tug toy for a reward so my fingers stay out of harm's way.

As for the chewing...dong's dont really chew a lot...unless it's bones...ever see your dog regurgitate his supper, it looks like perfectly formed, unchewed kibble (albeit slimey) I would make sure to give him treats that aren't so big that they'd get caught our training treats are usually the size of one of my fingernails.