I’ve also never seen “angst” take a plural form, in English or German. It’s an uncountable noun. But I suppose street kids could be starting to use it as a plural, as in, “Gonna go gets me some angsts.”
We’ll, they usually are uncountable. But if you have several instances of some emotion or mental state separated by other states, it’s not beyond English grammar to treat those as countable and pluralize the word. Or if you dread or have anger about several different things, those could be considered countable. You obviously didn’t read the link I gave about “happinesses”, where several reasonable examples of pluralizing that were given.
As far as verbing angst, try googling >> “angsting about everything”<< to get several thousand examples.
They were unusual or convoluted sentences, imo.
I’m completely open-minded about this, and it will be easy to convince me - just give example sentences to support your assertion that most of that list can be used as countable nouns. It’s not a theoretical question about whether English grammar has the infrastructure to accommodate their use as countable nouns. It’s an empirical question of whether we do it in practice.
We certainly don’t ever say “I have dreads about x and y”, or “I feel angers about x and y”.
So what are you claiming are valid examples?
I didn’t find them convoluted, and any examples I would make up about the others would be fairly similar. So it’s unlikely I could convince you. I guess we’ll just have to agree to disagree
But setting that aside, I trust you’d agree that
“I feel dreads about x, y & z”
is wrong
“I feel anxieties about x, y & z”
is okay
Any thoughts as to why, beyond what I wrote in #20, which I don’t find very satisfactory.
Aengste. Problem solved.
And here I thought this thread would be something about “angst” being used instead of “angry” by kids these days… 
Well, I agree that the words are usually uncountable and saying “I feel dread about x, y, and z” is using the word that way. But if someone had a different reason to dread each of them, I could see them saying “I feel dreads for x, y, and z.” It would be a bit unusual, so I’d expect an explanation for this construction.
But even for the first, I could see someone replying “Your dreads about them are irrational.” You may consider that convoluted or unusual, but I would just say they’re being clever or cutsie or something.
As far as “anxieties” construction, using the plural there would be essentially the same: different reasons for anxiety about the each of the three whatevers. If it were a collective anxiety, I’d expect the singular to be used.
Even plurals can have their own plural, as in “the peoples of the world”. Same with uncountables, such as “the waters of the Amazon” or “the moneys of the world”, which even has own separate form, and is correctly “the monies of the world”, which has no back-formed singular.
Anything that can be used as a noun can be expressed syntactically as a plural, but what I have a problem with is the dictionaries that don’t bother providing a correct form/spelling for all of them, arbitrarily excluding some as if to imply that they cannot be correctly used.