Nice theory sir Derp, you made me want to analyze Orochimarus character once again and this is what I came up with:
I think when he attacked the village, he was trying to test how strong the military force of the village against other villages invasion.
Had he succeeded he would have placed himself as the Hokage that will fortify the military strength of Konoha so other villages won't be able to invade so easily.
Even if he failed the attack in part 1, it would make Konoha ninjas more aware that they should always be ready for any attack so his beloved village will never fall.
I think he still cared for Konoha and like Jiraiya, Nagato, and Obito he wished for world peace. Although his way is to become the strongest ninja so no one will oppose his laws, in a kind of dictatorship. If you think about it most of the major villains aren't really evil, they are just extremist/radicals that would go to any extent just to accomplish their goal.
Although I still think that he might try to proceed with his original goal of becoming the most powerful and perfect Shinobi.
This is why I think he is trying to go up against Obito because he needed the power of the Rinnegan and Juubi. By becoming the next SO6P, he would become treated as a god and other shinobis would be too scared to oppose his rule.
I also think that Naruto series is running out of villains to oppose in the future so it could only be Orochimaru or Sasuke!
