My take on it is that it's emulating a interrogation. In each scene you mentioned, the characters all have hidden agendas.

Landa is a clear example of this, always trying to pull some information of of the opposite character(s). You can say this get reversed in his last "interrogation with Aldo Raine, where he is the one being fooled.

In Kill Bill, Hattori Hanzō is the one hiding information while Beatrix is the one "interrogating". This scene also stands out as the only one of the four that doesn't have a "bad intent" (every interoggation is followed by someone getting killed/hurt).

That's my take on it, though I would add that these long scenes filled with dialogue is kind of Tarrantino's trademark, so my theory may be a bit fetched.