One suggestion, and I'm not sure it works for you, would be to skip the ten day pass and get a AP. I don't think there's too much difference in cost at that point.
The biggest suggestion I can give to anyone taking a child under 5 (and I've done it a bunch of times) is to take it easy while in the parks, take long breaks at the hotel, and allow your child to direct you in what to do and how long to do it. If they're happy, you'll be happy.
And it's much easier to follow that advice when you aren't constantly worrying about getting your value out of your day. So, with the AP, you are free to come and go as you please. 2 hours here, 4 hours there.
That's how I have done every trip with my kids, and I've never had a problem with over-exhaustion or crankiness that way.