Yes, one person can book Genie+ for their entire group.
As for Universal, depending on when you're going in November, you might not need Express. Unless you want to power through everything in both parks in one day.
We're going on a Wed, 2nd week Nov. We're only planning on IoA, as it appeals more to my kids ages. But I'd like to avoid 1 or 2 hour lines, which is why I figured express would be worth it. If we ride everything once efficiently then there would be more time to wander around, see a show or two, and pick a few extra favorites to get in standby lane for 2nd try