Avoid state double jeopardy so state prosecutors can charge post-pardon. 1/
By not charging conspiracy/aiding/abetting, Mueller clearly leaves those charges available to NY state:
Count 1: Obstruction of justice
Count 2-6: False statement to federal investigators
Count 7: Witness tampering (with fed investigation).
assets.documentcloud.org/documents/5694…
It would be a stretch.
So Mueller brings the charges only he can bring. And he leaves the charges that state prosecutors could also bring related to computer hacking & trafficking stolen goods.
But making the Stone charges _pardon-proof_ is surely just as important here.
CORRECTION: "EVEN if pardoned..."