I was thinking through some of the game's dialogue, when all of a sudden I realized that some of it threw a real wrench in the works of the R=U theory. Specifically, the flashbacks dealing with Laguna and Edea. If you remember, it was stated that Esthar soldiers were looking for a "successor" to Adel. Now, if sorceresses can live indefinitely as long as they don't pass on their powers, which is something that the R=U theory seems to take for granted, why would Adel be looking for a successor? Adel doesn't strike me as the type to just hand her powers over to anyone and die unless she has no other choice. She's not much of a people person, and not much into sharing. If she could live forever, she would. The idea of her looking for a successor means that she is going to die, and she wants some say in what happens to her powers when she does. And if she was looking for a successor, the lifespan of a sorceress can't be too much longer than that of a normal person, since the successor would be dead long before Adel otherwise. Nothing else really makes sense.