I agree with a lot of your points. (And don't get me started on this newfangled use of "trigger".) It's hell indeed, because it's a sneaky bastard.
Mostly, I'm replying because grounding is your best mutha-effing friend when it comes to triggers. Won't work 100% of the time, but let me put it this way: It allows me to successfully be around my mother, the originating source of my PTSD, without panic attacks and without my heart racing faster than a rabbit on crack. It even allows me to laugh at her insanity rather than be so affected by it that I shut down emotionally for a month after a visit with her. (I still shut down, but it's only for a day or so now.) The coolest thing about it? It's customizable as fuck. Do yourself a favor, and do yourself a Google, and send those trigger moments packing. You won't regret it!
Unless you already know about it and use it, in which case...happy grounding, yo.