I'm sure you'll get different answers to these questions but here's what I think.
Q1...Did I have right of way because I was on it first or did she because she was closer to where the wave was breaking?
IMO..It's the person closest to the breaking part of the wave that has the right of way..even if you caught the wave a mile out to sea..

Well that's the way I look at it..(from a windsurfing/SUP'ing point of view)..I'm sure most surfers see it different and think the first on the wave it's there's.
If I ever see someone between me and the breaking part of the wave I either get off the wave or stay well away from them and ride the shoulder if possible..and hope they fall off..

Q2...Do I have the right to ride in between them while they are sitting on their boards or is that considered a no no?
IMO..Yeah...Go for it..

..as long as you are in control and you don't go too close to them.
Q3...Do I have to get out of his way or does he have to get out of my way?
IMO..You should avoid them..You have the control and speed to manover..They are sitting ducks and can only hope that you miss them..

Good on you for asking these questions because they're very important ones..

DJ