I read about that concern that you had, and I understand.
That awful— yet beautiful— stable I was at for a while had staff members who forgot to feed my horse several times. When I went to the “manager’s” office to complain, I was told, “Well, the workers are only human, and they sometimes make mistakes.”
Those anxieties were partially alleviated by my making two trips a day, around feeding times, just to make sure he was fed. Well, and by the fact that I left. 
Where I’m at now, I totally trust the hands-on trainer who also lives about 20 yards from the barn. I don’t fret about feed or staff supervision. Instead, my anxiety has become laser focused on my young horse, who’s so full of promise. I have periods where I worry obsessively about him suddenly dropping dead or becoming unrideable. So I guess it boils down to an overwhelming fear of losing something/someone I love dearly. Again. And not being able to control their demise and ultimate departure.
Oh wait…
Maybe you guys helped me stumble on to the underlying cause of my Equine Anxiety… 