Ok. Lets talk....
are P-F-T grads being hired directly from P-F-T into the B717 jobs or must they stop at some regional along the way?
No way! Actually most of those guys are Captains that went through the program and did there time at the airline. So, they were permenent hires after the F/O program, got Captain upgrade, then recently went to Air Tran. I think it was 5 or 6 in the past two months that got hired.
Also, how much energy does Gulfstream expend toward placing its grads?
They place an extreme amount of stress on their shoulders at the marketing department to keep this promise. If you don't get permenent hire, choose or don't get hired by Pinnicle, then the Program manager will do his best to get you a job at another regional. The leftovers from Pinnicle (some are leftover by choice) usually go to Colgan or Commute Air. I have only seen two guys not get hired by anyone. Honestly, if you don't pass the Pinnicle interview, then you need help on your professionalism. You and I both know that there are bad apples everywhere. <--- I believe this is improved grammar. j/k
Here, again, Russian, your comment begs the question as to why you would need to P-F-T in the first place.
First reason is because I wanted to. I know how good the program is and I want the training. Second, I have low multi time even though most of it is Beech Starship and CE-550 time. Oh yeah and the semen-hole too.

I did the math and with having to commute to Ft. Pierce (V-8 gas guzzler), the cost would have been the same at Ari- Ben Aviator to build the time in the Dutchess.
Also I talked to a lot of friends at the regionals, (ASA, Great Lakes, COEX, and GIA CA's although this is somewhat bias) and they actually insisted that my attendence at GIA along with my instructional experiance would not only put me ahead of the pack, but ensure me a slot at their airlines. (previous 121 training) Not to say that I am in any way guaranteed a job, but I want an edge over the competition. I don't see it as stepping on others toes because I have CFI'ed for many years now.
I also have neglected to state that I also don't feel great about a 500 hr or less pilot in the right seat of an RJ. On the other hand, GIA is great training and the pilots that it produces are top-notch. I feel that most of these guys are the only exception to the 1000 hour rule. However I cannot defend TAB and others because I have never associated with their final product. I also have always encouraged my students at GIA to get their CFI and instruct on the side to build real PIC experiance and knowledge. Most have taken my advice and done it, even for extra cash (starving f/o's).
Hopefully this calmed response answers some of your questions. I also enjoyed your response to my post. I think we just got off to a long, bad start. I just needed to take a step back (some of my peers weren't too happy with me either).