Firstly, be aware that squirrels aren't really supposed to get many nuts period. They're treats only and not a diet staple. That said, pine nuts are very bad, I think macadamia are No list too, and Brazil nuts are OK, but are SUPER high in selenium, so should be given in small moderation. Humans aren't even supposed to exceed five a day, and squirrels are just a bit smaller. And yes, peanuts are very bad.
I'll put a link to both the healthy diet thread:
http://thesquirrelboard.com/forums/s...-Pet-Squirrels
And to the calcium to phosphorus thread:
http://thesquirrelboard.com/forums/s...sphorus-Ratios
You want two parts calcium to one part phosphorous (2:1) as an ideal. Most foods aren't very close, and most nuts tend to be a fair distance from that ideal, sometimes terribly far away, as in the case of pine nuts.