I hope for these additions, too (but I don´t expect them).
I don´t think that the Reti-Slav lines are objectively problematic for Black. You should look at lines like (1Nf3 d5)
(a) 2c4 c6 3b3 dxc4 4bxc4 e5
(b) 2c4 c6 3g3 dxc4
(c) 2c4 c6 3g3 Nf6 4b3 dxc4 5bxc4 e5
(d) 2c4 c6 3g3 Nf6 4Bg2 dxc4
(e) 2c4 c6 3g3 Nf6 4Bg2 Bg4 5Ne5 Be6
(f) 2g3 Bg4
I play all these lines and don´t have any problems. You must prepare it!
I´m much more concerned about 1Nf3 d5 2c4 c6 3e3 Nf6 4Nc3, when White still might want to continue with d2-d4 and Meran, Schlechter or ...a6 lines. To stay in a "real Slav repertoire" Black must play Bc8-g4xf3 lines, but White´s pawn structure is more flexible now (d2-d3).
Another move order problem is 1d4 d5 2c4 c6 3e3 (again looking for a Meran AND avoiding 3Nc3 dxc4), when a "real Slav player" must allow 3...Bf5!? 4cd cd 5Qb3 Qc7 6Nc3 e6 7e4?!, a very unclear and dangerous pawn sacrifice. Very few master games, some claim White winning, others Black winning. I´m curious about Vigus´ opinion.
Of couse the Panov is no problem at all for Black.
tracke