Update from original poster:
Well, after a few weeks of all my yelling and chasing and throwing things (and possibly making my husband pee out by the coop), I am happy to report that our last two coyote sightings have simply been one walking past at a distance of 100 ft or so, not even attempting to come close. The chickens seem to have caught on that I will come out if they make a ruckus, so they've been good "alarms." Also, since the last two sightings were singles only, I'd say there's a chance somebody else shot or caught one of them (they had been running as a pair).
Our local newspaper just ran a story on the increased sightings of these bold, suburbanized coyotes, so at least I know I'm not alone (and it's also not just the hens, as we had coyotes in the yard before we got chicks hence why we built a very secure coop). I still have my guard up and will even more so in the late winter when they get more desparate, but things are okay for now. They seemed to have targeted my yard as a kill zone for about a week or two, and now have learned it's not worth it I hope. We are feeling much better about it anyway!
Thanks for all the suggestions and I hope this thread will be useful to others seeking solutions to coyotes as well!