I grew up in Germany but haven't lived there for almost 45 years. I pride myself in still being fluent. And yet, this resonates.
Nominative--Mein gutER Freund, my good friend. Genitives--MeinES GutEN FreundES, of my good friend. Dative--MeinEM gutEN Freund, to my good friend. Accusative--MeinEN gutEN Freund, my good friend.
Typing German in an email or Whatsapp, sometimes I get these details wrong and sometimes (shame!) I have to try a Google Translate from English.
The other thing he makes fun of isn't that strange. Splitting "Abreisen" for example (to depart) is natural because it's a compound word in the first place. And more over, in the example, the admittedly funny "De .... [flood of words] ... parted" it's not even one word, it's two (reist ab). German does lend itself to gratuitous nesting of sentences, but that doesn't mean that good German has to.
The first and the last are the same (nominative, accusative). Do they mean the same in German also? Surely you can't just swap one out for the other?
Nominative is used for subjects and accusative for direct objects. In “I bit the dog” or “the dog bit me”, “I” is nominative whereas “me” is accusative.