I feel your pain. We went through similar problems. Many others do to, if you look at the online support groups. Some things that might help you:

* Set user permissions really tight. I've had so many issues with users dragging folders around resulting in everyone re-syncing.

* Use a better desktop client. The Google one is really basic. We use SyncDocs which is more robust and has the features you need.

* Your API issues with jpg files are probably due to you tripping Google's anti-piracy system.

* Set up a separate Google Domain for testing stuff. You'll have to pay extra for it, but don't test on production data.