Ditto Chris on the sleeping bag; down as a rule (when cared for) is lighter, more compressible, and longer-lasting than synthetic.

I can't speak to the value of a BA Aircore, I've never played with it. However, I will chime in, somewhat to play devil's advocate to what Chris posted. I have both CCF and inflatable pads, and I'd be much more likely to use an inflatable on a long thru-hike. The extra comfort sleeping is well worth the extra ounces for a long hike IMO. But it's up to you and your comfort levels.

Yes, Tarptents really are that good; with some knowledge about site selection, pitching, etc they provide great shelter and ventilation for a lot less weight than double-wall tents. Six Moon Designs also has very well-like single wall shelters; I ended up choosing between a TT and SMD shelter only because a used TT popped up on this site. Depending on how much time you're spending outside a shelter, you might consider a tarp or tarp/bivy combo to get you through the odd night actually under the stars.

The Caldera Cone System is available with a lot of different windscreens, each compatible with the common pot/mugs seen. I'm not sure if the MSR Blacklite specifically is on the list, but a quick check of the internet or antigravitygear.com might yield some results.