Hi John,
1. Now you need to create a client as required in your case. Here you need to create a client with profile SAP_CUST from client 000 to 100.
Then use the profile SAP_USER profile from 001 client to copy the users to 100 client.
You will find good details regarding client copy in scn
2. You need to configure STMS to move the transport from DEV-->QAS-->PRD.
With Regards
Ashutosh Chaturvedi