Hi Paul,
ECFramework is the newest part of MicroStation SDK and from this point of view, it's not bad beginning. If you miss anything in the documentation (and I agree your request is valid and understandable), add your note to the discussion Updating the MicroStation Programmer Guide in BDN discussion forum.
What can help you is to check presentations and code examples from areas where ECFramework is used now ... and it's used widely as the "technology in background" in many product and tools, e.g. i-models, Symbol Providers or in interoparbility tools in Bentley Map.
With regards,
Jan