The thing is that all of those things only contain trace amounts, so they don't cause me problems. Also, the FDA requires that things containing MSG actually list it on the ingredients list. I'm sure there are people much more sensitive than me, though.
Also there's a big difference between free glutamic acid and MSG - they take the same metabolic path but they have different results along the lines. Unfortunately, conflating the two is a common scare tactic used by the fretful anti-MSG crowd, which ends up making all MSG sufferers look stupid by proxy. Like, when I mention my MSG sensitivity, I often get certain busybodies linking me to lists like that to "prove" that it's all in my head based on the fact that I can eat those things without trouble.
Basically, if something has enough MSG in it that MSG shows up in the ingredients list, it has a hell of a lot of MSG and is almost certainly enough to trigger a reaction in me. Presumably, people with an even lower threshold have to watch out for even more things, and I'm sure there's also other issues which lead to sensitivity towards free glutamic acid. The fact that there are several different common reactions that people can get to MSG tells me that there's a whole cavalcade of ways that it can fuck shit up.
When I cross the MSG threshold, I start out with a sort of synaesthetic sensation where I can "taste" salt in my eyes (as in, it's like I taste salt, but it's coming from my eyes instead of my tongue), which then turns into something that's somewhat like a migraine (it feels like someone's put a vise grip on my left optic nerve), and then that spreads all over my body and then I get a prickly sensation all over like I'm rolling around in broken glass. It's not particularly pleasant. I've had friends tell me that they get a similar reaction (and also something like that happens to my mom, so it's possibly an inherited trait), but I've also heard others say they don't get anything like that and instead they get a more generalized headache and then feel "puffy" and the like.
So most likely there are a few different issues which all just happen to be triggered by MSG.
I've also heard from people who aren't normally MSG-sensitive but after eating way too much cheap Americanized Chinese food end up having what sounds like the headache part of my MSG reaction, so that leads me to believe that at least for my particular reaction, it's just a matter of how sensitive you are rather than it being some particular inherited defect.