Not sure if you've resolved your first issue or not, but when you're on the Scenes tab and select a Trigger, scroll down on the right side and click Save to update the Trigger info. That should be reflected when you view your game on the Locations tab. Do you have a functional game or are you still in the site selection phase? If you google a bit and peruse links to/from this board, you'll find many helpful resources compiled by Chris Holden that provide a sort of tutorial on designing in ARIS. I'd definitely refer you to those resources. Start small and build out.
I cannot answer your question on reporting, but I share your interest in tracking player usage. If you include some kind of points system in your game, you can get a surrogate for your users if you build in a leaderboard. That will show you the users names of the top ten scorers who have played your game and not yet reset it on their device. So if your course is smaller than ten, that will work. Otherwise, I do not have an answer.
Cheers!