Thanks so much, whereismikeyfl. That is VERY interesting info, and to me, it makes the Mignini/de Guzman situation much more understandable.
I would say, however, that if it was Zaks' original idea to make Sarah Brown older, he really should have paid closer attention to the script and the song lyrics. Given some of the lyrics that Sarah sings in "I'll Know," she really does not sound like an older woman, rather like a young woman who thinks she knows exactly what she wants in a lover/husband and is very content to wait for it. Of course, even a young Sarah is still a highly unlikely target for Sky because she's apparently so prim and proper, and so religious. I've always thought that was the central conflict and chemistry of the Sarah-Sky relationship.
So maybe, when Michael Riedel was talking about this subject with Paul Wontorek in that interview, he didn't want to come right out and say that it was decided Carolyn Mignini was too old for the role, so instead he talked about a lack of chemistry as a euphemism.