Been busy last few days. I think I'll do mastic where the outside walls touch the drywall since those are thin gaps and can foam for the interior wall connections, since those gaps are bigger. Is a good mastic a joint compound like this - http://www.homedepot.com/p/SHEETROCK...9048/100321605.
I've also got a guy who will double the number of my soffit vents and replace my bad ones for an underside vent total of something like 416 sq. in on the bottom and the 240 or so on top. I may have him put in larger vents as well (16-8 instead of 16x4). This will make the majority of my venting on the bottom, but I think this will work.
Any other thoughts are always welcome. Thanks for all the help so far.