Just a theory but this is seeming more and more like a "dread pirate Robert's" personality. (hopefully there are people old enough here that get the Princess Bride reference)

The original masked attacker was Madara. This satisfies the questions of how come the masked attacker was an adult during the fight with the 4th hokage. Years after the kyuubi escape during 2nd ninja war, when Kakashi took the eye from Obito, Obito was found and saved by Madara. After being healed Obito was trained and raised by Madara after finding out about the death of Rin (hence him growing and reaching an elite level). This solution also satisfies the comments that Tobi obtained "his eye" during the battle of the bridge that made Kakashi famous.

As to why Obito is mad at Konoha and Kakashi, it is because of the death of Rin, whom Obito loved and cherished.

When Madara eventually died, Obito assumed the persona that Madara had developed and gave himself a new name, Tobi.

I believe this is the best and most likely solution for what has been going on. Any comments would be appreciated.