Welcome to NB.
There are many things in what you say that make sort of sense.
1: Kakashi has the left,Tobi has the right eye.
2: Kakashi Kamui sends people into another dimention, Tobi can send people and himself into other dimentions.(Kakashi uses MS for this though,Tobi doesn't)
3: Kakashi tried to Kamui Tobi and Tobi said it wouldn't work on him. Why?
4: Tobi & Obito both have the exact same letters in the name. Obito of course has 2 O's but still.
5: Tobi has said things which suggest he knows Kakashi and also tends to comment on his eye/ocular skills.
The issue I have is why would Obito want to cause pain to anyone?
He was a good Shinobi.
That said, it is possible that Madara found him.