Hi Ryan,
From version 7 you have properties based configuration, you can use for your purpose but has some limitations, not all task can be done using properties files. But most of the common operations you have asked for yes.
System administration for WebSphere Application Server V7: Part 4: Properties-based configuration (beware with some commands sintax, there is some problem with page coding)
www.ibm.com/developerworks/websphere/tec... Managing environment configurations with properties files using wsadmin scripting
pic.dhe.ibm.com/infocenter/wasinfo/v7r0/... Using properties files to manage system configuration
pic.dhe.ibm.com/infocenter/wasinfo/v8r5/... Hope this helps. Tell us if you need more support.
regards