Can I add a driver down the road and have them covered?

I asked the same question in the office last week & they said Spouses in California are automatically authorized & covered. I "think" and you can ask about insurance coverage for non-spouses.

Yes

Yes I believe so as long as they go in to office with you with valid id. You would need to call them to confirm this. I have added the day after I rented and id was all that was needed