Philip
Donor
But if Savoy couldn’t be kept on board would the young son of Charles VII, Maximillian be able to bring them to his side when their promised the Duchy of Milan and maybe Mantua too.
It's not enough to promise them land. The Franco-Bavarian alliance has to likely to win, likely to fulfill the promise. Better performance early on by the Bavarians is one piece. Keeping the Prussians appearing to be committed to the long war is another. If these happen, Sardinia may jump in with only minor concessions. At worst (and good enough for Max), they stay neutral (and maybe permit French troops to pass through their lands).
And if George II was offered more land for Hanover and maybe have Hanover elevated to a Kingdom, would he switch sides, and if so how would that work with Parliament and everything?
I don't see this as possible. Geopolitical pressures elsewhere keep the UK and France opposed.