A sandbox Mode would be my favourite, but with limited funds (with a optional u limited funds mode) to keep it interesting. Building a Park with anything in it on Nublar would be a dream.
I can't really decide whether I want the original JP or the remains of JW. I kinda like both ideas. So if I could have the option to play both, I'd be completely satisfied. So that's what I want on Nublar. Also kinda hoping for Sorna to include the remains of the bases we've seen in TLW and JP3.