A question about Susano.

[SimpleGenin]

1) While the jutsu is active, is it completely seal in?

With Sasuke's fight with Mei, Mei melted Susano's bones but it did not really harm Sasuke. Doesn't that mean while the jutsu is active, the caster is protected in an air tight space?

For example will Deidara's C4 bomb affect Sasuke while Susano is active?
Or would water get in Susano if it's inside one of Kisame's water dome?

2) how excactly does Susano protect the caster? It's kinda a weird question. For example, what if Pain's ST hit Itachi/Sasuke's Susano, how would it affect Susano itself? Would it push the caster? Or the susano entity itself?

[gama-sennin]

Mei's acid mist simply proved that Susano'o is not as durable as it is hyped to be. Its durability greatly varies depending on user's chakra reserve and the opponent's strength. It is possible to break the defense using a sufficiently strong technique.

[SimpleGenin]

So is it air tight?
From the fight with Mei, it seems like it is. How else would the acid melt the bones of Susano a feet away from his face.

[gama-sennin]

May be its just a feature of Susano'o. The user is safe inside until the attack breaks down the entire bone structure.

[Nyruss]

If it's airtight, that's one more way to beat the Sauce. He can drop it so he can breathe or keep it on to stay protected and suffocate to death. I approve.

[Akatsuki X]

That also kinda brings up my past question that no-one was able to to answer as to if Susano'o has weight to it.