Question about the production: did they use mics in the same way Spring Awakening did? Handhelds for the songs?
Yes, many of the songs incorporated hand-held mics. Not all, though (i.e. "Since I Don't Have You," "There Are Worse Things...," group numbers, etc.)
In the pre-Broadway tryout, Megan Mullally pulled her hand-held out of the pink toilet for "Freddy My Love." Like the rest of the revival, it was a cute moment not to be taken seriously.
musicalfandukie, thanks for the reminder of Vanessa Williams. There was a thread on here a few days ago that I kept posting on so I thought it was mentioned. However, the Pearl Bailey recording was done for when she brought the show to New York after she toured across the U.S. and Canada after her stunt as Dolly. So, the OBC was closed by the time the record came out so it's seen as the recording for the 1967 "revival" with Pearl Bailey and Cab Calloway, although the production was the same costumes, sets, etc as the OBc (if I remember correctly)
Pearl Bailey's initial time in Hello, Dolly! was not considered a revival. She later starred in a revival in 1975, but her performances beginning in 1967 are included in the 2844 performances of the original run.