I finally had to give up on X10 and switched to Insteon a few weeks ago—I signed up for Stringify just this past Wednesday, June 27, 1018. I set up a flow triggered by an open/close sensor on my front door to turn on a light only if it's nighttime, only if arriving in the area, blah blah blah and it worked beautifully. I was thrilled and began building more complex flows for alerts and so forth. As of Thursday afternoon, none of my Insteon triggers seem to work. I've spent all of my downtime today troubleshooting, disabling flows, changing "things," and still no luck.
My workaround at this point was to set up my hub to send an alert to Gmail, then configure Gmail to apply a label based upon the subject line, then swap the trigger (open/close sensor) for a Gmail "thing" as a trigger for my original flow. THAT works, but it is completely Rube Goldberg and pretty lame.
I've seen a few other posts about Insteon's API not necessarily being reliable, but since I'm so new, I don't know if those issues have been sorted out. To answer your question about #2, I also noticed that the Stringify app does not necessarily update the status of a thing. This may be related to your #1 and the problem I'm describing. I wish I knew why this was working perfectly fine on Wednesday and now it's not.
I hope some folks between Stringify and Insteon sort this out. They both proclaim to work with each other, so one would hope it would be in their best interests to make good on their promises. For what it's worth, I know that Comcast now owns Stringify and I'm a Comcast customer, so how about it?
Also, when I check Stringify status (http://status.stringify.com/) and expand "Things," Insteon isn't even listed. UPDATE: It is listed. Not everything is alphabetical, apparently.