My choices:
1) I would redisgn the parking lot for sure.
If money was no object, I'd buy the mall and level it and move parking over there and expand the park. Make a whole new section starting where the current back gate is.
2) I'd redesign the traffic light and the whole exit from the parking lot. The thing is a bottleneck and it is a huge mess on a busy days like July 4th. I'd also retime the traffic light so that it would let more than 3 people out at a time!!!
3) Hyper under the bridge. You knew that was coming.
4) More flats - A good frisbee and top spin would be very popular at the park. They are also fun for people to just sit and watch as well. Just go watch Tomb Raider at KD and see how many people are just sitting and watching.
5) Buy some new swings! I'd really prefer a Yo-Yo set than the older design, but either would be fine with me. Install them back where our swings used to be.
6) Buy a GCII coaster that's even better than Thunderhead. Period. End of story.
7) Take out Vortex and install a new B&M floorless that's very tight in that same spot but still has a lot of inversions. I'd say remove Cyclone, but it doesnt' take up that much space.

Sell off the park because it's in too much debt from all the rides I just bought! lol j/k