thanks for the replies. so contrary to the Roxul site info, you're saying, Gary, that I should not use a poly vapor barrier under the sheetrock?
Also a question regarding sealing up my "weep system". Since I likely won't get good adhesion of blueboard to the poly sheet, should I proceed by using adhesive at the top plate and bottom flange(or concrete floor) to the blueboard edges, tape and frame in, say 8' sections(to fully support the bb). then maybe foam and bb the top of the wall framing perpendicular to my rim joist insulation job. hoping for some clarity on sealing up this weep system. Also, would 2" bboard be enough insulation by itself. If roxul is overkill with 2" bb, I'd rather save the money. i really appreciate the info. thanks.