Sasuke can absorb chakra without breaking the Bijuus from the genjutsu the same way Orochimaru absorbed his chakra from Kabuto without breaking him out of Izanami. You have to infuse your chakra with the victims chakra to disrupt the chakra
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. Kurama wasn't near the core, he was more outside of CT then had rocks come on top when Nagato did it while Kurama is the core so have layers of rocks on top of him and it was completely sealed. Nagato was using his CT on Kurama's lower form then he powered up to 8 tails mode so no it's not the same thing. Try looking at the second scan in OP, Kurama's eyes are normal before it closes up on Sasuke's Rinnegan so he was already out of it before that so Sasuke was freeing the Bijuus from CT only for the looks of it.
It doesn't constantly squash them, it seals them inside, they wouldn't feel the shockwaves from Naruto and Sasuke's Attack because of that and as for the fall they are really durable to take tbb from each other and not be seriously harm when it's landscape changing tbbs. You disrupt someone else's chakra flow by putting your chakra into another and do it in a high enough amount the it disrupts it. Orochimaru absorbed his chakra from Kabuto and didn't break him out of Izanami nor was that his intention.
Alive Madara did that but Edo Madara didn't, alive Madara is stronger than Edo Madara and he wasn't blind in the sense that his eye lost their power, both eyes were actually close to him, Zetsu popped up after Madara escapes the Bijuus and gave him a Rinnegan and Obito have the other a short distance away. Obito tapped into his other eye just for being near it, he was able to see through it and when he saw Rin died he leveled up both his eyes up to 3 Tomoes and gained MS.
Orochimaru doing it with Kabuto is good proof there and it was never said taking chakra would work the same way since to disrupt the genjutsu you need a stronger flow but taking chakra wouldn't increase the chakra flow but lower it
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. The genjutsu most likely wore off after the Bijuus were sealed.
Bee wasn't a perfect Jinchuuriki, he only lived because Bee cut him out via tentacle before he was taken so Bee didn't feel the shock of having the 8 tails ripped from him. That's why the 8 tails said he'll go back to Bee.