He he, calm down guys.
As to the OP, this game is as close to a military grade simulator that you're ever going to get. The last game I can recall that actually did something like this before was Steel beast pro, which had a price tag which was more than a hundred dollars.
As for the tech you listed.
DCS-A10 is multithreaded in that the sound engine runs parallel to everything else.
PhysX is good for neat effects that render on your GPU, nothing that you can rely on to make game critical calculations.
DX11 over DX9 is also not much to gain compared to the cost, at the end you'd get an easier way for the programmers to do neat effects, not something to spend a lot of time and money to port to if you already have an engine and your main selling point ain't those neat effects.