Basically, without a CHL, you can carry in your car, your house, and your office (if your employer allows you to). It must be concealed at all times. It's best to use it when you are absolutely sure that your life was in danger. If you take your gun out of your car, shoot, and kill someone, then you might end up being charged for killing them.
Yep different laws for different types of firearms also.
The Texas State Rifle Association or something like that, used to have a booklet with the specific laws. I will see if I can find a link.