Yes I don't see why not he received training from the dragon cave. But the dragon cave is different you can absorb natural energy while moving like juugo for.instance. but kabuto needs to get out of Izanami before he can be of any help.
He should be able to, but it's kind of understandable if he can't. I assume he was able to control the senjutsu chakra mostly because his chakra pool was enhanced after taking in all those shinobis' cells. However, he did learn the technique on his own so I think he should be allowed to keep the ability.
Really not sure. Kabuto said that Orochimaru's body couldn't handle SM yet when Oro's chakra got taken, DSM got removed. It's kinda hard to tell but I hope he can
he can't for god sake.he was able to achieve a snakelike sagemode thanks to the chakra and dna of oro in him..this was the reason why the snake sage taught him sagemode in the first place.but now he is empty and stripped of his snakelike attributes which aided him in learning sagemode..though he still has the chakra of he sound four and jugo's dna...but this wont be enough to enter sagemode..he needs that.,.that...that....oro dna and chakra that taste like weed...for him to go kaboom lol
I always assumed no, but now that i think of it i changed my mind.
He couldn't use sage mode because his previous host couldn't handle the natural energy, but now that he possessed a body made out of Hashi's cells shouldn't that problem be solved.
Edit: And now i feel stupid because i read Orochimaru instead of Kabuto -.-