Darn, we were ok without the attribution as that was specific to the static APIs, but you are 100% correct on the restriction from mixing it with ESRI maps. The clause:
(e) No Use With Non-Google Maps. To avoid quality issues and/or brand confusion, Customer will not use the Google Maps Core Services with or near a non-Google Map in a Customer Application. For example, Customer will not (i) display or use Places content on a non-Google map, (ii) display Street View imagery and non-Google maps on the same screen, or (iii) link a Google Map to non-Google Maps content or a non-Google map.
Specifically forbids the use of what I am doing. I guess it is better we found out about it now before this version of our app goes into production and it causes a problem.
Thanks!