i might be biased (i love the idea of relius/irene even if i melt into a puddle of goo at the merest whisper of gen/irene), but i really do think he loves her.

i mean, if he loved wielding power so much, i really don't think he would have considered so seriously retiring into the country & opening correspondence with the magus (ugh i wished that would have happened. i can totally see them becoming bffl's, haha). the only thing that kept him at court was irene (i don't have the book with me right now, but he says something like "even if she kept me here for fifty years, i would grovel at the chance to serve her again") & i don't really feel that that's the attitude of a man who wants power.

he seems content to be subservient, or at least subservient to irene.
feel free to disagree, i just felt like putting in my two cents. :)