I do like some of your ideas. Maybe swap out Tidal Wave with Trypticon. Second movie sounds good but maybe leave out the Vok. I think Unicron would work better as a decepticon creation/secret weapon but it works the way you have it to get the bots and cons to have to fight together against a common foe. & 3rd movie keep 2 1/2 hours max for theaters with directors cut the longer 3-4 hours.