Yes, but you said Limbo was irrelevant. If the shadows can knock around avatars, that can leave a huge opening for Madara to strike. It took some time before the Tailed Beasts could get back up. The duration of rest is pretty short too. It only took about a minute, the time for Sasuke and Naruto to converse and do their combination attack on Madara.
The rest time for Limbo isn't long, but you're saying that Madara can take on the opposing party by himself using Limbo, which means to me that you're implying he can't without it. Over the course of the battle there will be periods where he can't use Limbo if only for a minute or so.
Limbo knocks everyone down, then what? How does Madara capitalize on the situation when removing the Biju from play isn't feasible?
Incorrect in a sense. The only thing said was that the shadows were still outside. They hadn't attempted to attack during Infinite Tsukuyomi. Also, neither Naruto or Sasuke have Six Paths chakra here, so Limbo can casually bypass their avatars at will and attack directly.
Sasuke stated that it was too dangerous to go outside with Limbo still out there and the IT light still up. The conclusion that logically follows it that Susano'o did grant a safety net from these things otherwise Sasuke's statement doesn't make much sense.
No, I don't think that Limbo has selective permeability since that isn't hinted at, nor do I think that was the author's intention. It's only stated that you need Six Paths Sage chakra to damage it. No special chakra is needed to make physical contact.
Sasuke's sword went through it, but that can just be interpreted as it ripping through Limbo without doing any damage. Sakura's punch made contact but did no damage. Sasuke's non sage chakra enhanced Chidori spear made contact but did no damage.
It's not likely that Limbo has an innate Kamui-like ability.
I don't think any techniques can be formed while under the Demonic Statue's domain, as that would've been the obvious choice of attack against Madara in the story. If it is possible, it probably uses up too much concentration and would lead to being sucked up in an instant. With Limbo attacking as well, it would be too difficult to counter.
If teleportation can escape the Demonic Statue, which is most likely, then this method of winning certainly wouldn't work, but it's still not the only way. With Limbo, Madara can take on the opposing party by himself whether in close-combat or using avatars.
I proposed that the chains get cut up before they even bind Kurama. With Majestic attire in play, Susano'o can cut the chains while Kurama attacks the statue directly with Bijudama. Even if Majestic Attire gets caught somehow due to Limbo interfering, the chains just get cut.
But yeah, Hiraishin makes Biju extraction unlikely.
