obito died long before the accident. and we don't know if itachi was pursued and if he were the hokage probably would have sent anbu after him.
Still, killing even a hundred member clan in separate houses and lingering around in his own home would most certainly result in a much larger situation than they seemed to imply.
Then again, yes: we weren't informed of how big the pursuit was.
All of them have/had sharingan ...
itachi is h4x. but he's gotten weaker over the ages, so he's no longer god-like (see all previous encounters where he was repelled). kakashi did mention that using the mangekyou sharingan deteriorates the health of the eye.
and obito is probably dead. the requirement for the mangekyou is the kill your closest friend. kakashi probably merci-killed obito when he was pinioned under the boulder.
They're all from the same clan
I disagree. Itachi is way stronger than what he has shown so far.
He never went all the way.
He used his MS most of the time because it saves time. But he has a lot more to show us when the time comes.
Just compare him to Kakshi.
Kakshi is a very strong Shinobi. He is smarter than Shika, has a better Sharingan than Sasuke, better taijutsu than Lee and tons of jutsu.
But he realized how foolish he was to believe he could kill Oro if he gave his live for it.
And we know that Itachi is stronger than Lee.
He could perform seals so fast that you can't even see it (even Kakshi couldn't if I remember correctly).
And in his fights he never really wanted to fight seriously. Or it was a weak "clone" that got beaten.
He is still very strong.
"For Feanor was made the mightiest in all parts of body and mind, in valour, in endurance, in beauty, in understanding, in skill, in strength and subtlety alike, of all the Children of Illuvatar, and a bright flame was in him"
... actually, how do we know that kakashi didn't have MS from the beginning ? certainly, he was never really pushed to use it.
sorry to break it to ya but everyone knows the story line.. Sasuke will kill Itachi... and Naruto will kill Sasuke.. you can already fortell the story.