I couldn't get through all the tl;dr, but my eyes lighted on this, which I can't help interpreting this as some poor agent's misguided, doomed attempt to be nice with a rejection:

“I’m sorry. We did receive your revised manuscript in August, and we appreciate how much work you must have done. Unfortunately I’ve been sick and had to go to Frankfurt for the Book Fair, and I just haven’t had time to look at it again. In fact, I’m so busy at the moment, I think I’m just going to have to say No. I can’t take on any more clients at the moment.”

I know, I've done the same sort of thing myself, as an editor, not an agent -- see, no matter who's doing the evaluating, rejections are going to happen, sorry. And sometimes rejections happen because, just in the pitch process, the writer comes off as way more high-maintenance than you know they'll ever be worth.