As I have been corrected you only get per diem during training. Until you start OE.

2500TT is the bare min for FOs. Not sure how much multi they're looking for but I think you need to have some sort of turbine experience.

Yes you get per diem away from base. Typed too fast earlier to edit what I wrote after.

I think they're trying to change their interview process to actually having face to face interviews and maybe sim evals.