1) In general people do not maintain the TM. If you stall or reach the point that you should not increase the TM, then you should probably decrease it. Generally, people just go back a few cycles then try to set new rep PRs and such. You can also do what Wendler has said about 5 forward, 3 back to reset before you have to.
2) If you are at 2 reps, you should probably reset. From Wendler's recommendations for different particular programs, you should typically be able to get 5, or at least 3, solid reps with the TM itself. So, I would reset to a lower TM rather than increasing it.
3) Wendler also has new recommendations about the TM that have been touched on in the forums and are to be spelled out in the new book. I will not attempt to spell them out, but perhaps someone else will.