test Lab?

I am setting up a test lab for Windows 2000.
It will start with one server and one client.
First I set the server up as a child domain is this correct? I want it that if I screw up the test server it will have no affect on the production servers. I set it up this way because I needed access to Domain resources.

Second can I install Exchange 2000 on my test server with out it interfering with our regular Exchange server? I need to retrieve some data from a public folder and I cannot do it on our regular Exchange server because I cannot selectively recover data from the public store like I can with the private store.