ok, i gave my friend the links, and heres what she had to say:
huh. OK, well everything they list is technically correct. You have to be careful interpreting exactly what it means. Things like silica don't hurt the skin but they can abrade mucus membrane and cause scar tissue formation in the lungs if inhaled. Does that make it harmful? Yes and no. No in a liquid foundation, YES in a powder foundation you might inhale. Many of the ingredients they list are exactly like that.
PEG is a polymer that comes in different weights (string lengths), it forms strings. I use it everyday to precipitate DNA out of solutions, add it and the strings tangle up other stringy things and make them glob. It's a primary ingredient in Paula Dorf eye transformer too. (Yeah, since I make cosmetics I did a lot of reserach into these things, so lucky for you I knew it off the top of my head!) when mixed with water and your shadow, it causes the shadow to be stuck to the strings and stick well. As you can imagine, this compound and others related to it make solutions feel thicker, that's why it's in everything and anything that feels thick.
Polybutene, in most lipglosses with high shine, is a petroleum product that is also used in car engines, to give slip and lubrication. It's harmful effects aren't really studied or known, it's basically plastic, but you should pay attention to the warnings about abrasions and injuries. Injured areas have migrating cells trying to come back together to heal wounds. Stick a glob of sticky strings in there and the healing is very impeeded if not f*cked up and can lead to scarring.
Cosmetics is unregulated. Most of cosmetics is not color but binders and fillers, to give texture, grip, opacity, and long lastingness. I personally hate most pure color products, like those *better for you* ones they list simply because they don't perform well. That's a fact. Blush I would hardly worry about because it's far from your eyes and lips, but eye products and lip glosses are, technically, generally really really bad for your body, chemically speaking.