Woah, that's one of the most awesome analysis on Suzaku I've ever read (especially the Kururugi heir part, I seriously never thought of that, but it makes sense).

I'll go with 'he doesn't want to care anymore'. Real!Suzaku may be bitter, but I think he's genuinely a nice person. I also love the fact that they didn't show his face when Lelouch was all screaming 'NOOO! DON'T DO IT!!' to his father. It gives the whole scene a very, very good touch of I-don't-care-ness from his side.

I'm still getting vibes of Lelouch caring for Suzaku when the golden Knightmare appeared. Don't fall to the same hole twice, Lelouch but we know he will.