Longtime lurker who's glad to see you back and might as well start chiming in:
I think maybe there's something to be said for rejecting the whole "flaws/virtues", because they usually go hand in hand: a postive trait in a certain situation, or in moderation, can easily become a negative one. "Interview flaws" are irritating when not realistically applied, but I think they can be good for challenging the commonly held standards of behavior or morality.
You seem to have already covered most of what I want to say here, but I remember when I was first starting out I was terrified of creating some sort of Mary-Sue character, so I would come up with flaws for characters. I ended up with an otherwise relatively saintly person who for some unknown reason had a "temper" and would suddenly begin to berate his friends and family members. Flaws have to be carefully considered so that they're cohesive with the rest of the character, his life experiences, his backstory, ect., or it's pointless.
Eh, I'm rambling at this point. Thanks for posting these rants, they've helped me more than I can say!