Sharing "Seats"— How does that work?

I have recently upgraded to DevonThink 3 Pro level, and I was pleasantly surprised to find that I had an extra seat to share. That raises a number of questions.

I live in France and I want to share at least one data base on a family project with a cousin in the USA. So he downloads DevonThink 3 and tries it out. What do I do to give him my extra seat? Do I just send him my license code? Or must I arrange the sharing through Devon Technologies? I know the sync will work well because I have used it intercontinentally with DT To Go on a research trip.

Once he has his seat, who controls the license code, or do we each have independent control? This could be important for the next upgrade.

If I have control, can I turn control over to him? This could be important because both of us are getting pretty old and one may want to drop out of our project. When one of us dies, does the survivor retain his current seat and recover the seat of the deceased?

My cousin has two Macs. May I purchase an extra seat for him?

Please contact Heike regarding this inquiry.