re: the post-Tony absences.
As far of time of year - by far, the best time to see shows is May. All the spring shows will have opened, and during Tony voting time, there should be no scheduled absences and all nominated actors will be performing unless at death's door.
Personally, for my trips, since I pack all possible slots with shows, I make it a point to schedule my least-preferred show for my arrival day, since flights from the west coast typically arrive around 4:00 or so, without delays. Also, I sometimes find "dark" plays disconcerting in the afternoon, so for 2 show days, I'll tend to schedule lighter musical fare for matinees.