There isn't any US law though, each state has it's own law. This settlement agreement was brought under Florida state. What I'm unclear about is whether this still stands in the current case which I believe is being brought under New York law. The NY lawyers seem to be arguing the agreement doesn't apply on that basis.
There is some federal law but yes, this is about state law.
I don't see that the argument about it not having standing in New York will fly. If it did, VG would have been able to take Epstein's money then sue him again in a different state. My understanding is that their argument is actually slightly different. I think they are arguing that Andrew was not a potential defendant in the Florida case and therefore is not covered. Given the wording of the agreement, I'm not convinced that argument flies either.
I've given the wording on page 2 some thought. My view is that interpreting it in the way suggested on the Eddie Mair show means it contradicts the previous paragraphs. I therefore suspect that is not the correct interpretation. I think it is intended to stop Epstein using the agreement as a defence against cases brought by other complainants, and to stop such complainants using the agreement as evidence against Epstein. However, the courts in New York may take a different view.