Access photos from Google Photos/Drive with iPad Air 2 I'm currently storing all my photos on Google Drive/Photos (auto-upload from Android, but also manual uploads of photos taken with various cameras). While I can sync Google Drive with my MBP and add the synced folder to the OSX Photos.app, this is not an option for my iPad Air 2, as disk space is much more limited there.

Is there any way to point the photos.app to Google Drive?
You can install the Google Photos App and access your photos from there. It works in a similar fashion as the Photos app on iOS, you see device sized photos and download only the photos you wish to copy to the Camera Roll. You can even sync your photos with drive if you like to.