I think it's a bad theory. There are many factors that make it impossible. If Suge killed Pac then - he nearly sacrificed his own life for it, he made the biggest mistake in his whole life business-wise and also did a bitch move by setting up his friend. I don't believe that it's even slightly possible. Orlando and his people killed him - after all I know (including all known facts and some semi-rare info I collected for all those Pac-die-hard-fan years) I'm 99% sure, 1% being random gang bangers, gangsters taking out their hitlist target or the government