I think the main drawback of the Google Maps API is that we can't add our own vector data or raster imagery as one of the layers in the map. Is this correct? Or is there any alternative in the Google Maps API.
If I want to add some more features to the existing features, can I do it in the Google Maps API for free?
What are the advantages of the recent developments of OpenLayers or any other client-side scripts over the Google Maps API?
If I use the Google Maps API, I think I need not require any database, webserver etc...because everything - the creation of features - is done directly using Google Maps API. Is this correct? What should I prefer to use?
I am asking all this because I want to do a project based on webGIS and I am thinking of providing a webservice for my city. Can Google Maps API alone do that or would it be better handled by OpenLayers or LeafLet, or something else?