^ as iron said don't roast them too long and keep a close eye on them unless you like eating charcoal.
As far as a change in macros, I've read that roasting them for too long can cause hydrogenation of the unsaturated fats which is a bad thing, but i believe it requires high temperatures for quite an extended period of time. If you keep it lightly roasted which is what we're after when using it to make nut butter since we just want some of those natural oils to ooze out, then it should be fine/similar in terms of macros.