I think the reintroduction of the Jimmy into the lineup is a great idea especially in body on frame form. When looking at midsize suv's most are unibody with a tow rating of 3500 - 5000 lbs. The Jimmy should better that rating. The 4Runner can tow 6000 lbs and the Grand Cherokee 7200 so target...
I'd love the small rear window to be functional as well but I think the decision to make them fixed comes down to crash test ratings. Same reason we didn't see Ttops considered from 2010 - 2024. The Camaro concept from 2006 also showed the small rear window as being functional but didn't make it...
I think making the next Camaro slightly more practical than the 5th gen might work to convince buyers it doesn't need to be a third vehicle. I daily mine through all seasons and put snow tires on in the winter. It can accomplish all the things you've listed with the compromise coming in the form...