is it safe to install peel and stick membrane on sip roof and walls

Opinions differ, but the consensus is no. You always need a way for a structure to dry if it gets wet(it shouldn't happen, but if it does). With SIP tape (should be required) on the inside, the outside is where the moisture must go.

I do recommend a 'peel & stick' membrane around all openings(extending inside) and at the exterior corners.

You mean like on the  front cover of JLC Feb, 2008? I remembered this as I was reading it just the other day. I am not SIP knowledgable, but why not on a roof?

Thanks,
Nick

You need to consider what the climate is where you are building.  What work best up north does not work the best down south.  Hot, humid climates dry toward the inside, Cold heating climates dry toward the outside.  This determines what side of the wall assembly to seal and which side to allow for drying of the wall assembly.  Building Science gives some good information about this http://www.buildingscience.com/bsc/.  The publish books regarding best building practices in different climates.  They even have a new book on building with SIPS but I have not had a chance to look at that one yet.