Thanks for the great update on Gizmo, he is doing real well it seems. I wouldn't worry about the foot, greys hold a foot up close to their chest at times, they are resting that foot and you should see this happen very often when they are just sitting on a perch.
He is becoming more comfortable so he is relaxing more and becoming more vocal, you will see more of his personality now that he is settling in.
They do like to attack and growl at those toys, bells especially are a favorite of Josey, she can get downright vicious at hers sometimes.