2 is easily solved by placing the attraction entrance on the park-side of HRRR, so everyone is single file by the time they get to the narrow portion of the path anyways. That does introduce another problem. There would be 3 attraction entrances at approximately the same point of the path, and that point is already narrow itself and very close to the entrance.
I think a likely scenario is that nothing happens. It gets used for productions, HHN, etc. just like the other sound stages. If anything were to happen, it'd the ability to build at the NY facades.