Not really, he wouldn't be an original owner hence he would be a lot weaker than those who awakened it.
Yeah, he'd need to obtain an Uchiha body (he currently has a body made of Hashirama Cells, so he could cultivate those and attach them to his new Uchiha body.
Beyond that, Orochimaru is a beast in terms of his knowledge of jutsu. I believe that, if he had the Rinnegan, there's no way he'd let himself fall into a situation where it's him against the world (which is what every other villain with a Rinnegan has done, besides Sasuke, who WOULD have done it if Naruto hadn't stopped him).