Oh, I'm not saying he wouldn't indulge in imperialistic behaviour, with the proviso, if he thought he could get away with it. That is, he would attempt to avoid starting a general European War- or at least one targeted against the USSR and himself. Or he could get a stroke, but it's certainly not a, hm, certainity. After all, he had strokes in OTL, and he didn't start a war with the Allies, despite that, so...
I'm not going to argue against you regarding RA2 (after all, I am a RA-Tiberian Traditionalist), but, to be fair, both of the things you mentioned are from the expansion.