Are you aware that you can use your fusion table as a layer on the standard Google Maps API rather than using /embedviz ?
https://developers.google.com/maps/documentation/javascript/layers#FusionTables
That should give you more control over how it's rendered. On a separate note, I'm not sure if this is relevant but I came across it:
https://developers.google.com/fusiontables/docs/articles/fusiontables_styling