Hi! You will be able to take the 2 yr old on any ride without a height restriction. If you go to the WDW website, there is a list of rides that are restricted by height that you can print out.
I have to tell you to keep in mind that he or she may be scared of a lot of rides in the parks. I took my 2 yr old in July, and he's a pretty outgoing child, and he was scared of pretty much everything. I was very surprised!!!!!! I thought yea, maybe he will be scared of the HM so I skipped that, but never imagined he would be scared of IASW!!!! I don't want to sound negative, your 2 yr old may be ok, just wanted to give you a heads up. I was pretty disappointed because I wasn't expecting it to be that bad.
Some rides with height restrictions off the top of my head are:
Space Mountain
Splash Mountain
Big Thunder Mountain Railroad
Goofy's rollercoaster ( I think it was 35", your toddler may be tall)
Rockin Roller coaster
TOT
Dinosaur
Kali river rapids
EE
Soarin
Mission:space
Test Track
I'm sure I am forgetting some, but I was also a little surprised how much the little tots could go on!!!!!
As far as the Pooh sized thing, my sister took her 3 yr old w/ us in July, and she (Pooh sized) fit fine with her daughter on every ride. I don't think you will have a problem.
Have fun!!!!