485 relink, Pjiang, please help, I read your Bloc

NIW 140 approved, 485 filed in 2007.
If I file an EB1 and relink the NIW 485 to EB1. What would happen if EB1 got denied? I want to use the EDA and AP.

Also, what's the priority date of the EB1 after relink? it is the future filing date or 485 date in 2007?

Thanks.