I'm still in initial training, so take this with a large grain of salt, but from what I've heard:
1) A new class started last Monday, and the bottom person should be about #1852 on the list.
2) I think it is a two year lock.
3) Depends on the plane; Airbus probably not more than a few months. 757 more like a couple years.
4) The 757 is mostly long-leg two & three day trips. The 737 has a lot of three day trips with more shorter legs per day, but is mostly day flying. The airbus, being the largest part of the fleet has the most variety. The vast majority 'bus trips are three or four days, with quite a few red-eyes thrown in. Sometimes you'll fly four or even five legs in a day, then the next day has just one trans-continental leg. Very few of the trips on any of the planes are one-day trips.
When I get back to PHX I'll try and post a couple 'typical' trips for the 'bus.
HAL