Typical roster 5+2 but with the odd 6+3 or 4+1 thrown in to change the days off.
For t+c, the stuff on ppjn.com is fairly accurate.
Roster stability isn't great. The rostering department are good (on the DH8 fleet anyway), with rosters published a calender month at a time, and normally issued around the 10th of the previous month. The problem is Crewing, who keep making changes on a far too regular basis.
Don't think any of the bases have night stops rostered, but as I mentioned, Crewing are the problem.