I think that for the people who wants to understand the
K.R. the better thing is to read his letters.
There is very big book printed in SPB in 1999 included the letters from K.R. and to K.R. of the following famous people: Pyotr Chaykovsky, I. Goncharov, A. Maykov, A. Fet, N.Strakhov, Ya. Polonsky, L. Maykov (unfortunately in Russian).
The apartment of K.R. in Marble Palace is also could saved without any changes.