Sounds like a good recipe, NW. Sometimes I'll hide a little butter inside for extra yum. I usually go simple: S&P, maybe minced onions. Your burger size and dimpling technique are spot-on.
I also like my burgers medium, give or take. If your grill or pan is cranked, and the burgers are at room temp, you can get rare by just doing a very quick sear and flipping once. Depends on thickness, but if I want to go rare, it's maybe 90s. - 2m. per side, but again, variations to heat/thickness mean you'll need to experiment. Take them off and let them sit under foil for a couple of minutes before serving, should be no issue with cool centers.
Also don't worry about wheat/soy in my Worcestershire, given the scant amounts I use (usually Caesar dressing).