I have been able to create a custom field through the Metadata API, which is great. But now to be able to use it, I need to be able to add it to all appropriate Page Layouts and Make it available in the WSDL.

So first question, how can I add a custom field to a Page Layout with the API?  I tried creating a Layout object (inherits from Metadata) and using the Metadata API call create to create the new object which causes a "Field Integrity Exception" with a message of  "Parent entity failed to deploy" so I think that I'm close, but the message doesn't really mean much to me.

Second, once I create a new field, I want to be able to query for it.  Is there a way to dynamically update the WDSL to reflect the new field?