I agree about the Muppets, that's the main reason we choose that area, to make it better, as from what I could see it definitely needed the most help. Something Grand Avenue style sounds like a good plan!
And a dueling coaster sounds like a great idea, as it's something the park doesn't have, and will help solve the icon problem, all of this area re-do can surely be done with the 170M budget! However, if you think it might need a little more, I can make some cuts!
Also, I was wondering if you wanted to take the Park & Project intro, as you have more knowledge of the park, so you might be able to do a better job than I in that area, and in consequence I can take the Indy area, as it's a smaller scale project.