Orochimaru, like he did with all his potential bodies, wanted them to come to him. SO he wanted to give him the curse mark.What? where does it say Oro was trying to give Itachi curse mark?
That first fight oro got owned. Itachi didnt even have to point his finger to put him under a genjutsu. There is not really any excuse for that first fight, oro just ran away after he got his arm cut off, deciding to go for the easier target (sasuke)
They are basically equal in this vs thread yes, but without your restrictions of the legendary weapons and edo tensei, Itachi is on another level to oro
Either that or try and take his body right then. Which he would have to capture him (to take his body).
Also, if you noticed in that fight.....Orochimaru wasn't in his prime or trying to kill him. He was forty-something. These are the years where you start getting weaker.
And I'd like to say this, Orochimaru wasn't full power......and is one of the villains who hasn't died yet.