CRT starts at report time in your base and ends upon return. Unless you show at 0001z on day one and finnish at 2359z on the 17th then 82+ in 17 days is unrealistic. 75 ish average would be my guess for 17 duty days. Just a guess though.
That is correct. Plus 5 days off between trips or the rig clock keeps running. Minimum off between 17 on is now 7 days off unless you wave it so no more 34 days on possibility. Not that it happened very often.