The highlighted part seems legit. U_U
First of all the 2 non uchiha's with the sharingan have it covered. Kakashi has his covered with his forehead protector. Danzo has his covered with his bandage and the ones on his arm with some metal coating thing all in the effort to stop the chakra drainage, danzo did however boost his energy with hashirama dna and but still took these precautions.
Tobi has only 1 eye covered and his sharingan has been on all this time, if he was not an uchiha he shouldn't be able to do this. Secondly controlling the fox is no small feat, only an uchiha i believe could do something like that. Using sharingan genjutsu to get info out of konan about nagato, but also using it on danzo's two bodyguards. His s/t ability where he warps others into another dimension is superior than kakashi's and he still doesnt seem like he suffers any chakra depletion, unlike kakashi who uses kamui once and he is already out of breath. He just seems like an old ass uchiha that has mastered the sharingan to be able to keep it activated forever no different to itachi. He has never suffered from chakra depletion using the sharingan
As for izanagi although danzo was able to use it, it was incomplete whilst tobi boasts a complete izanagi, the reason that is, is because he is an uchiha.
Basically true uchiha's = incomplete (itachi for example)
Non uchiha's with hashirama dna = incomplete (danzo for example)
True uchiha + hashirama dna = complete (tobi for example)