Can't help on the foam question - I've never used the stuff plus our typical building environment is quite a bit south of you.

I've always been skeptical of foam encasing roof decking and framing due to breathing issues, but again, I have no first-hand experience with the stuff.

Again, you confirmed my worries about the house breathing. Around here the foam insulation is great for under the house and walls but when I asked about the roof, he said "we can do that to" I think he misunderstood that I was asking is that good to do and is it by code! We are going to do just under the house and the walls. The ceiling we will do with the R-30.
Thanks!