With a whopping 2 years on the property I can't answer all the questions, but here are some attempts at a few...
Hub turning if flying into Mem from an outlaying city, waiting for the sort, then flying back out to the originating city. The "typical" night hub turn has you leaving from the originating city at 2000-2100 local, arriving in Memphis just before midnight, then leaving MEM again around 0300-0400. There are also some "day" hubturns leaving the originating cities around 0600-0800, arriving Mem 0700-1000, and going out 1500-1700 that day.
Nice thing about schedules like that are many have a commercial DH to the originating city on front and back end. This makes for a very commuter friendly company. We also don't (usually) hub turn on weekends, although there are some out Saturday return Sunday day flights. International and SIBA trips may be completely different--I'm speaking mainly of the bulk of the 727/Domestic A300 flying.
Mixed into this are "out and backs"...leaving Mem 0200-0400 and returning 0500-1100 that day. Memphis based folks love these as they spend 4-8 hours away from home but then are back by mid day. We also have day O&Bs which leave around 1500 and RTB 2300-0100....you show up late but you go home at night (if you are MEM based)
Not all flights meet these parameters, but I'd say 65-85% are probably close.
So...week on/week off schedules are possible and as Spur pointed out--we rarely fly weekends and the 1 in 7 rule would keep you from consecutive days hub turning anyway.
Ramifications of latest accident on crew force and hiring? Who knows? I have found almost everyone I've flown with at FDX to be the utmost professional, and the training department folks are dedicated and work hard to keep us sharp. I have no idea why/how these accidents occured, but I'm sure flight safety, mgt, ALPA, our own MEC, and the NTSB will have some findings and recommendations. Until then, I won't speculate and I'll try to stay out of everyone's way.
I have had 3 line checks/observations checks in year, as well as a PC (sim check) and a PT (practice sim). I don't know what if anything the FAA will do but at least as an FE I feel well trained and prepped for my job. I would expect, however, more scrutiny on future flights from FEDS and other outside agencies, but that is 100% pure speculation.
As an MD10/11 wannabe I could insert a crude joke/comment here with the punchline being they need more guys like me in that system, but whenever I've jumpseated the widebody guys have impressed me with their dedication and professionalism. I would love to be in MD10/11 training tomorrow, but this is not the prefered way to move up in seniority. I have no idea what happened, but like every other pilot on the property I'll be waiting for the NTSB final report with great interest.