This looks great
One question is whether most of this will ever make its way outside the US, like much of the stuff in Google Now failed to. e.g. parcel tracking cards never worked for me in the UK version (even for services like UPS where the US side was already implemented with the same API, which meant I had a parcel which started tracking when I visited the US, then vanished when I flew back again).
I noticed a lot of the Google region-locking is implemented on the client based on its location, so the API and everything was working the whole time, it’s just your client that decided to give you the middle finger once it realised you were no longer in the “good” locations.