Very unlikely. The younger son presumably had the original Will of Fire being the original Senju. Just because Tobi coincidentally did things (I agree a very little bit on the sealing part but...) that Senju/Uzumakis did doesn't mean the older son is out of the question. Also the Eye of the Moon Plan involves achieving peace...with power. Wasn't that the philosophy of the older son of the SO6P? And many of your points could go towards saying Tobi is the older son too. It was a good attempt at a guess, but the older son seems to fit a lot more.
Also like others say, use the sticky.