Let's go through those points.
Below I've used the numbering found on Benny's list, but I've reworded the titles to better encapsulate his points.
2. Americans use the word "awesome" too much and Americans use of phrasing skews things to be more positive than they are
Every language has its overused words. In Brazil, everything seems to be legal ("cool"). In Japan, it's all 凄い sugoi ("awesome"). Do these words lose some of their original oomph when constantly used? Sure; legal comes off as closer to "OK" at times, and sugoi gets toned down to just "good" in some cases. But to complain about this, you basically need to set some arbitrary linguistic point as "the right meaning", label anything else as wrong, and not accept that language changes over time and space. Benny seems to have set European English as his standard, and his complaint is pretty much that American English doesn't match the standard.
The same thing applies to Americans' supposedly overly positive phrasing. I never have any trouble figuring out how someone's doing when I ask them in America, so it sounds like Benny just hasn't gotten accustomed to U.S. English yet. "Great" in the U.S. might equate to Benny's "good", and so on for all the other examples he cites, but it's a vocab use question and not some malicious cultural tendency to obfuscate about how Americans really feel.
My favorite example of this not-saying-what-you-mean-according-to-foreigners thing is in Japanese. If a Japanese person says 考えておきます kangaete okimasu ("I'll think about it"), what they almost always mean is "no", but don't want to say that directly to you. However, everyone understands what that means and no one thinks twice about it—except for foreigners who aren't in the loop yet.
9. Americans use "I'm Irish" to mean "I'm Irish-American
This is another vocab use issue, which Benny himself notes when he says "I use country adjectives more restrictively than Americans do". In the context of the States, where there are relatively few straight-up foreigners but almost everyone is an immigrant or has ancestors that came from some other country, saying "I'm Irish" and meaning "I'm Irish-American" pretty much never creates any confusion.
3. Americans smile too much
What if I raised this complaint when traveling?
In my culture, body language x means y. In this culture, body language x means z, and they use it too much, so it's bad!Pretty silly, I think, but that's just the complaint Benny's making about smiling. A smile in America certainly doesn't usually mean "I'm gushing with joy at your presence and intend to light up the room with my smile", but it's probably something more like "I'm welcoming you to engage me", which in Europe might simply be conveyed by eye contact. Faulting a different use of body language is just as pointless as faulting a different use of vocabulary.
Let's take a quote from Benny and apply it to a parallel situation to see if it works any better:
Goddamnit America Japan – … [y]ou guys smile bow way too much. It’s fucking annoying! How can you tell when someone means it? And why the hell would a stranger doing a crossword puzzle sudoku on public transport want to look giddy show respect?Nope, still silly. (This exact situation happened to me just this morning, by the way, although I wasn't the least bit annoyed by it.)
In all three of the items above, Benny's basically faulting American English (whether the language itself or the accompanying body language) for being different than his English. If he wants to keep his English in line with what he likes, he by all means should, but I don't think the "it's different so it sucks" line of argument carries much water or is ever a helpful attitude for a language learner to take.