How can I load a view inpage using AJAX when a node is flagged?
This is actually a pretty common functionality and there is a module for it, Views Flag Refresh: 


  Views Flag Refresh allows site administrators to configure which views are refreshed automatically via AJAX when certain flags are selected. This is useful when you have a view that filters by flagged content and you want the view to be refreshed automatically when content is flagged or unflagged elsewhere on the page.


If this doesn't fit your exact needs, there are lots of code snippets in the Flag Javascript API Documentation that might set you in the right direction.