I think I have an idea about the letter strings, it's probably been mentioned already but it sounds about right because of OWI stating how simple the answer actually is;
\\//\/KDIUTHANPUYHHDQOEPLNDOALJGUDITHBBDOZLGFERKJGLSAOE
My theory is that much like the mastermind puzzles, the slashes tell us which parts of the text we need to keep, and which need to be discarded. I'd suggest something like segregating the letters into 6 equal chunks to correspond with the slashes, and then removing the ones that aren't "true", then caeser shifting the remaining letters to give us a message. Naturally that hasn't worked yet.
Basically, I think they're saying to us you don't need ALL of the letters there, and the slashes are a formula of how to work out which ones are relevant. And then because it's gibberish, we probably need to shift the remaining letters.
It's that age old dilemma that we're all thinking the same way, and the answer is probably right in front of us, and we just need to slightly change our thought pattern to see it haha.