Yeah I was thinking mite webs for some of it (the main pics clearly show some kind of web). What would be your guess as to what it is?

Some of it appears to be a type of mold though, as you can see in this shot. Sorry for the quality of that pic, I'll try to find the same spot or some others that look similar and will post more pics... it's a tiny section of a leaf, so it was tough to steady it enough without losing sight of it.