Thanks everyone for all the helpful suggestions! The Crayola Experience was a really good option for us, given the age of our kids and our time and $ budget. Not sure it's somewhere we'd ever go again, but it really did the trick and I never would have found it without this thread.
FWIW, even without rushing, we were at the airport (via DME) by 8:25am, bags (for free) en route without our interference. Not sure why someone thought that was an expensive service? Had our rental car and were out of there by 845.
Anyway, we went to the Crayola Experience and it did the trick! We got to the Florida Mall well before it opened at 10, so the kids played in the play area and looked at photos from the trip and all that. We left Crayola for lunch, wandered around, came back, and successfully killed time until 3pm. Were at the airport by 3:20 and at our gate well before 4 (our flight was actually at 5pm. I know I said 7 originally, that's when we landed. Whoops).
I know people don't like to rush, and neither do we, but I've never missed a flight. We are lucky, and have pre check, and with Hertz Gold (free to join) you just park the car and walk to the terminal. So it really takes no time on either end.
Thanks for all the helpful suggestions!!