As Nikolaos said, you can't use an API for one product to communicate with a completely different one. API stands for Application Programming Interface, therefore an CRM API is interface for communication with CRM and F&O API is an interface for communicating with F&O. The name itself tells you what the interface is for.
F&O also offers more web services than that, namely custom services and data management API. As usual, you can find more information in the documentation: Choose a data integration (import/export) strategy.
The question about filtering metadata was recently discussed here - you can find at the discussion to read details. But in short, you must download the file and then extract what you want. If you have more about other topics than what belongs to this thread ("Is there any Web API support?") and you don't find answers in previous discussions, please create new threads with appropriate titles.
