Right. If you're going to frame AWAY from the wall, as you describe, you DON'T need the venting I described. Since you have the gap, you're allowing any moisture back there to 'breath out'. So, you can skip that part. I did fail to 'recognize' this since most folks furr off of the wall itself. If this is done instead, one would want to at least drill 'vent holes' in the top plate of the new wall to let moisture out. If you haven't considered a dehumidifier since it's gonna get damp down there anyway, now's the time to do that. Since the unit will generate water as a by-product, you can construct a small sump pit and pump the water to the outside.
One key to a dry basement is to let it do what it's gonna do assuming you've done EVERYTHING reasonably possible to prevent it from getting moisture. But as you already know, (and as I already mentioned), it's gonna get damp anyways. Soooo, in a sense, let the moisture come it then get rid of it w/a dehumidifier. In doing that you should be OK in the mold/mildew dept. Do understand this - M and M need 70+ degrees, high humidity, and a constant source of water/moisture to grow. If you can sufficiently reduce/eliminate any ONE of these variables, you're pretty much 'controlled' your problem. The heated basement is going to 'draw' moisture into it. So, let it. Then get rid of it w/the dehumidifier. That's what I was initially referring to when I talked about the vents.