OK bernerbits, I just read every single one of your posts in this thread. You should be commended for your extraordinary efforts in this case. Try to resist the urge to be an armchair analyst, however. Unless your wife experiences equally long bouts of crippling depression to go with her bouts of mania (usually lasting several days, weeks, or months, not just several hours), she likely is not suffering from bipolar disorder. Since you mentioned Aunt Flo, it's
possible that she is suffering from PMDD, which is basically like PMS during that time of the month only the hormone imbalance is exponentially worse than what is normal and it can lead to wild mood fluctuations including rage and aggression. Of course, all I have is a B.S. in Psychology (well, 2 weeks from now I will
), so take what I'm saying with a grain of salt (i.e., maybe mention it to your marriage counselor as a possibility).
Secondly, you are absolutely taking the right step by initiating couples' therapy. Don't worry about seeking out individual therapy -- a proper couples' therapist will see each member of the couple once or twice to evaulate if individual therapy for one or both of you would be more suitable. If she (or you) does indeed have some mental disorder, the therapist would likely refer you to have that sorted out first, and then engage in couples' therapy afterwards.
As far as your worry that the therapist may side with your wife, it shouldn't happen but it does. One of my professors (who is a female couples' therapist, by the way) recommends that in relationships where the husband is shy or timid and the wife is aggressive and/or very talkative and outspoken (which seems to be the case for you), the couple might do well to seek out a male therapist.
Bottom line, my recommendation to you is to find a male, licensed couples' therapist (with a Ph.D. in clinical or at least counseling psychology) and move forward from there as he recommends. Good luck, and it's very smart of you to try to tackle this so early on in marriage, rather than waiting a decade when all bridges have been burned.