Sasuke cant get to chakra mode. You have to rid the Kyuubi of its hate and seperate its chakra from that to unlock its pure form.
Sasuke is filled with hate he will never find its true power, nor does he have a safe place to fight Kuruma with an unlocked seal.
Rid the Kyuubi of its hate? All Naruto did was accept the hatred inside him. Sasuke has long known that he has hatred and vengeance.
1. Minato was an Edo when he used it therefore had no physical restrictions. When he was alive his body was unable to handle the volume of chakra he absorbed.
2. Minato had a body strong enough to absorb and control NE, Sasuke doesn't.
Furthermore, Sasuke will never be able to get passed KCM since Kurama hates Uchiha. And even his KCM will be weak in comparison because he doesn't have the chakra reserves to maintain it for long.
1. That's an assumption. He was numb at first but that's because he's never held such an amount of chakra. He knew full well before absorbing it that he would be able to handle it.
2. That's also an assumption and a bad one at that. A random has more body power than Indra? Controlling the Kyuubi is also different than training to learn Sage Mode. Any Mangekyou Sharingan user naturally has the power to do the former.
3. I never said he would get past KCM, though you saying an Indra incarnate wouldn't have the chakra reserves to use it is rather lopsided. They are known to have the largest amounts of natural chakra only behind Ashura incarnates. We also can't even measure Naruto's own amount of chakra. Hashirama himself said Naruto was below him, and he may have even accounted for Kurama's as well, which would really be a blow to Naruto's natural reserves.