For a fellow Navy guy I'll reply.
Don't sweat the ATR sim, its a breeze. Only surprise is how much it rises when you drop the final flaps, expect to push nose down and trim, especially if anywhere near glide slope intercept.
I did the interview thing at ASA, got hired but went elsewhere.
Right before the sim my evaluator did a 1v1 with me to "discuss my experience." It was a bushwack. He asked me aero and systems questions, so be ready. (How does an airplane turn?, etc.) The sim profile was really basic. Takeoff, climb outbound on a radial and level off, turn to intercept another radial (to prove you can use a CDI), he failed an engine (use your own EP) then gave it back, turn to intercept and fly ILS to a landing, breaking out at minimums.
The toughest part is the length of the day. Starts at eight and my sim was at 6pm - and I went first which I highly recommend.
Don't sweat the stick and throttle, but study Jepps and airline FARs.
Good luck.