Hi, and welcome!
Sorry to hear about your wife's experience. Her actions sound, to me, typical of someone who's recently been through an LGAT -- and your reactions are also understandable (I reacted the same way when my friend went through Landmark).
The way you're approaching things right now is really the best, although difficult. Because your wife is on a "high" right now, she will see any negative comments about her new group (and new "friends") as an attack against her personally. Try to remain supportive and loving while doing as much research as you can into these groups. I've heard it helps a lot to talk about happy times before the group involvement, to remind your wife that it is possible to be happy outside this group and to remind her of how much fun you've had together.
Groups like these do try to separate people from their loved ones (their support systems), because it helps make them more dependant on the group. So as difficult as it is, try not to play into their hands.
I'm not very familiar with PSI 7 (sorry), but here are some things to read that you might find helpful.
A psychological study of Lifespring (another group) training:
Some books that are helpful:
Cults in Our Midst, by Margaret Singer
Releasing the Bonds, by Steve Hassan
If you're really upset, you may want to get in touch with Rick Ross...he's the expert in these matters.
I know you're going through a tough time right now -- try to hang in there.