As far as the chemical burnt paper goes, I’d just make a dulpicate layer of my paper layer and get it lookin sweet in photoshop, i.e. play with some layer modes and grunge brushes. Then I’d import that back into AE and parent it to my original paper layer. Then animate a mask around the acid splash, making it expand accordingly.
Good luck.
Oh, and sometimes some really nice, convincing sxf can really help sell the effect.
I shot all the green screen elements in one day, created all the graphics over the period of one week, and then took one additional week to complete all editing.
Thanks for the input. I might make them a wee bit smaller.