I'm pretty sure that Freelancer was suppose to basically be a sand box style game set in a Starlancer like universe, but all that's left of that idea is a few tid bits here and there.
If you look at the early development cockpits, they looked like they worked more or less like SL ones, and I'm pretty sure that Heavy Lifters were meant to work like the Ripper did and I'm sure there are other things I haven't thought of out there.