As for the throttle sticking, try letting it warm up and get it to stick (preferable in neutral/park to be safe). Once you got it to stick then try disconnecting the throttle cable completely from the TB and seeing if it'll still stick (by giving it throttle right at the TB with your hand). This might give you an idea of whether it's the TB or throttle cable.
It could be that the throttle cable is kinked somewhere causing it to stick. OR maybe the throttle body itself is faulty and sticks when it's hot.