1st same abilities. Except Tobi and use it on himself, while Kakashi can use it on other's. There like opposites. Would make sense if they where both using the same type of eyes.
2nd How did Kakashi awaken the mangekyou sharingan? Easy when Obito awakened it, that meant Kakashi's awakened at the same time. Same eyes.
I could name more but I dont want to bore you with the details. and no there is no way he can be zetsu. Sure his hand may have been made of zetsu but remember. Obito was said to have died in the grass village. The village Zetsu is from. Mabey Zetsu found him and restored him back to like by putting his cells into him.
:doug: