Things one can do to test the waters: Ask former employees about the job. There was a job in Florida I knew was being advertised and I asked two pathologists who worked there and they both painted horrid pictures of the markedly unfriendly work environment. I would certainly ask around, shouldn't be too hard to find out about pathology groups. Ask minions too, PA's / histotechs / and lab workers know others who may be able to put you in touch with the right people concerning pathology groups. High turnover is a pretty bad indicator that the group may just in LaDoc's words "looking for someone to sign out meat." I would keep an eye on that. Same thing for academic jobs, I see lots of residents thinking they gonna be solid staying in academics and it can be just as virulent and petty as bad private practice jobs.
On a personal note I do not believe anything compares to interviewing at the group/lab. I would open your eyes while you interview and tour the facilities, one place I went, not only was the pathologist markedly weird and distant (and vague about benefits), the whole lab looked depressed, these may be small signs that should turn a warning bell (is that gonna be YOU in that chair in 6 months).
As far as contracts, usually they will keep the main hospital contract unless someone goofs up royally. I used to worry about individual clinicans/surgeons, but they can be so wishy washy who they send their stuff too at times there is really not much of a point in worrying about, I just do a good job and if they are happy they will stay. Its a good idea to try to weasle out as much info as you can about a group because just out you will be spending an incredible amount of your time at work, I certainly can only hope you find a good place.
I would definitely have an attorney look over your contract, out of training it may be expensive (to review mine was about 1600 dollars) but they really look at it hard and take out redundant b.s. and advise you on things to watch out for. I thought I was smart enough to look at it and to me it looked good, but they point out the small things that I never even thought may be a problem.
At absolute worst case scenario, if you end up somewhere and it isn't what you are looking for, at least you will build that experience to be wiser on the next job hunt. I would never feel bad/guilty for bouncing from a non-desirable work situation, you didn't suffer this long to end up miserable I hope.
Hope this is useful information. Good luck in the job search, I wouldn't want to be in those shoes again.