With his age it's hard to tell if it will turn into agression or not. Sounds like its a mix of play & little aggression.
You say he may have a bad start to life, maybe he's not used to toys & doesn't know how to share them, that would make sense, he wants to play so thats where the running around grabbing things come into play yet he's unsure so he snaps & bares teeth.

It sounds almost like he's just getting too excited for his own good and has not where else to put that energy. Since you say it happens at about the same time every night I'd try to stop it before it starts. Try taking him for a walk, or play in the yard about a half hour before it starts. See if that wears him out. A tired dog is a good dog.
You certainly want to reprimand him as it is not an acceptable behavior no matter if it caused by play or aggression.