One thing that it does not often get mentioned is that German fighters (and their engines) in the last two years of the war were built in scattered facilities and largely by slave labour: in those circumstances their performance often was not as good as it should have been according to factory...
AFAIK the pattern was vaguely similar but not identical. For the aircraft in the second photo, the colours are said to be Black 33, Neutral Gray 32, Sea Green 28, White 25, Rust Brown 34 and Sand 26.
The book does cover the whole history of the E-Stelle. I believe that Mayer was heading E2 from 1943 onwards, but I cannot double-check right now. I am sure that you will enjoy reading the book when it arrives. Unfortunately I have had precious little time for any reading lately, due to work and...
For what is worth, the section on Peenemünde-West in this book was written by Max Mayer, who worked at the Erprobungs Gruppe E2 at the time, but I can find no mention of Kaaden (who might have had a junior role there), and certainly no mention of any Me 262. Erprobungs Gruppe E2 was in charge of...
If it was a weapon at an experimental stage, KG 200 would not be involved, but rather one of the E-Stellen, probably Tarnewitz or Peenemünde, or even Rechlin.
"Spitfires Rampant" by Bill Tatham is a very good read on the exploits of 4 Sqn SAAF's dive bombing Spitfires in Italy, if you are after first-person impressions...
I am sorry to tell you, but that was the normal camouflage for day fighters introduced with the LDv 521/1 of 1941 and confirmed by factory drawings from MTT: 02 and 74, together with 75, were to be used for the mottling on the fuselage sides, even if in practice the colours used for this purpose...
"Shade 04 for naval aircraft camouflage has been abandoned" could just be a reminder that this had been ordered in a previous communication.
The use of Gelb 04 was limited to upper wing surfaces, IIRC...