Yes that latex will work in your molds.
Use grease make-up or what is called rubber mask grease make-up. It will stick to the latex well and you can blend it into the skin.
The cheap way to go with the glass is make candy glass. We did a short film a while back where we used it for a victim of a car crash. Also, I think there is some haunt company that sells fake silicone broken glass pieces. They would work as well, or Smooth-on sells a product to make it yourself.