Dave,
You've asked many questions and if the thread stays alive I'll try to get to all of them.
Regarding length of time, the fastest recording I ever made was one of Handel's complete WATER MUSIC that I conducted (
http://www.hbdirect.com/album_detail.php?pid=215803). The ensemble was the Chamber Soloists of Washington -- all members of the National Symphony (save solo oboist Allan Vogel) and very comfortable together. We rehearsed 3 or 4 times and recorded 60 minutes of music found on the the disc in one 2.5 hour session (essentially a sound-check and 2 times through the piece). The results were marvelous.
My recording of Vivaldi, Albinoni, Baldassare, etc. with Concerto Rotterdam (again, mostly Rotterdam Phil. players) was rehearsed for concerts and then made in two sessions -- perhaps a little bit more typical than the Water Music disc.
As for programming, I've never enjoyed recital disks. I prefer programs with "a point of view" -- music by one composer, from one period, or tied together my some relationship hinted at in the title and explained in the liner notes.
More, if you and others really want to hear it...
Best,
EC