I'm not sure if the ADAM database stores info related to whether the machine it is hosted on is domain joined or not. I think you would need to get this from the machine itself by querying one of the various APIs that can provide this.
The password policy in effect (unfortunately) cannot be queried from ADAM as ADAM defers to OS level calls for password policy enforcement. I assume you have to use some sort of LSA Policy API to get this information from the local machine, but I don't know exactly what API that is.
The policy in effect could either be set locally or applied through a GPO, although I don't know how you would determine that either. It probably isn't important where it came from but instead more important to know what it is.
This is one of my biggest grips with ADAM. It really should support is own password policy mechanism with mulitple policies like AD 2008 now supports.