Yeah, I didn't go into too much depth on the umami booster part of my post, but this is pretty much spot on.
I often add some Thai fish sauce (usually Tiparos brand) - it packs a punch. And of course Worcestershire sauce is basically just a doctored up fish sauce. Soy sauce works too, but it's such an instantly recognizable flavor that it really needs to be used with restraint, lest you end up with a big pot of 'Chinese chili'.
Those umami mushroom powders can take some caution and experimentation, too. I tried using the Trader Joe's version, and it was just way too intensely mushroomy. The McCormick version is more balanced, with onion and garlic powder. I'm thinking about trying it out as a base for a BBQ rub...