Good summary. Most important to me are that (a) the bonuses come early, and (b) they're passive, so they help you no matter how you're playing. Not sure they're in aggregate any better than most Civs, but these two points make Rome an easy civ to do well with. That said, I'm not sure why the AI doesn't do better with Rome. Possibly it puts too much production into Legions and then doesn't get much benefit out of them.