What's the usual cut-off for NT in d2? Mid-50s have a shot?

Mid 50's is practially a lock.  At  projection 55, there'd have to be 9 teams below you win their CT. 

A guy in my conference (N-10, D-II Crum) was 59 in the projection report last season and made the NT as a 15 seed. Another guy, also last season, was 62 in the projection report and made the NT as a 16 seed. That's a pretty small sample size, just from one season in one world, but yeah, I'd say mid-50s definitely has a shot.

It mostly depends on how many conferences are completely SIM. The more empty conferences, the more teams below 64 on the PPR will win their CT for an automatic bid, thus lowering the cut line. For example, in d3 Wooden the cut is generally around 42-44 (b/c of so many empty conferences) but in d2 Rupp it's often in the high 50s b/c every conference has about 4 or more human coaches.