1. So your telling me that zetsu had been making tabs on people before the akatsuki was even formed, and that he just happened to be watching kakashi when obito died? Because kakashi doesn't talk about obito, or at least we've never heard him say a thing about him. And then you have to consider that zetsu is not everywhere at once. Up until this war he had to choose where would be convenient to watch. It's not like he has tabs on every single ninja, academy student to kage. That's a really stupid assumption. If he were to have kept tabs on kakashi and obtained this information it would have to be when obito died and it would have to be for a reason. Zetsu would not be watching a squad with a simple distraction mission for no reason. And what intrest would tobi have in that information? Tobi might have wanted to kno kakashi's regret for psychological purposes, but why would tobi care that guy did not remember faces. Its either he asked for that specific piece of information, or he sits down a nd listens to everything zetsu has to say. And if zetsu is just making random tabs on everybody then zetsu would have a lot to say. I doubt that tobi would have the time to listen to and retain everything that zetsu had to say to the point that he would remember the minuscule non important fact that guy doesn't remember faces. Logic Flawed.
2. Danzo is a non uchiha member, yet danzo was able to influence the impartial samurai's decision at the five kage summit. You don't think that with a good amount of practice and training, an uchiha could do the same? Madara and tobi have been confirmed to be working together, so of obito is tobi, when madara enlisted him he would have probably helped him grow stronger and utilize his sharingan, and probably taught him his space time ninjutsu, seeing as how up to this date outside of video games those are the only 2 things he uses. Alas, I digress into speculation. My point is, if a non uchiha is able to do this to an adult, an uchiha with help and guidance from madara uchiha, with about 6 years in-between where any amount of training and practice could have occured, could not do the same with a child? Your logic is not flawed here but is very challengeable and I think it's plausible that with the help of madara obito could have greatly increased his potency with his sharingan to such a level.
3. That hurt bro. You were pretty wrong, but that still hurt bro.