When publishing to the chrome store....
1. Does it cost anything?
2. Can we charge money for our chrome apps?
b. If so, do you get any profit?
1) No, this is a free feature.
2) You can charge what you want. The vast majority don't charge from the store. If they do charge, they offer their own store for doing it.
In what language will we code for this? Javascript, AS3, or that other universal language you are/were considering?
This is just for Flash games right now - Google's store only works with content that can be played inside its browser, so it's either that or HTML5 games.