Heh, maybe I should have put that standard disclaimer of mine in the previous post to avoid confusion. I'm not actually part of the Peachy team, I'm just a fan of them who has dome a good bit of research along the way of them making this project happen. I'll answer your questions as best I can, but I don't know any of their internal decision making process.

I can't for the life of me think of an additive that reduces surface tension in oils (or in this case monomers) and if there were one, I can't imagine it having a positive effect on the hardened polymer.

As I said at the beginning, I don't know their selection process, but they did go through several different laser diodes before settling on the one they are using. And the skinning effect I described is at a very small scale and possibly unavoidable without a complex focusing lens setup on the laser that would bring up the price too much.