"It's" vs "its" is also bothersome, but for a different reason - this probably has to do with learning English in a way that emphasized formal sentence structure, rather than just the way it sounds. But I think that's not all that uncommon for non-native speakers. When I studied in college in New Zealand, I once had a chance to converse with our ethics teacher (native Kiwi) one on one, where she remarked on my spelling in a recent essay. From there she quickly went on to a general rant about how immigrants are much better than natives at spelling, citing "its" vs "it's" as one of the examples - according to her, she had never seen a non-native speaker substitute one for the other inappropriately.
On the other hand, "if I were" never made any sense to me, and is one of the more common mistakes I still make, even after 8 years of speaking and writing English 99% of the time.
Before reaching that level, however, they have to deal with truly maddening stuff like how to pronounce word like "read" or "tear" or "close", or why it's "an interesting little book" instead of "a little interesting book", or why you can see a movie but you're not "seeing TV", or the fact that both "thir-tee" and "thir-dee" mean 30.
Languages evolve to suit the needs of their speakers. If people find themselves without words to describe something succinctly, languages will evolve to become more expressive.
I think compound nouns (as used in German) are a good example of this. They make the language more complex and harder to learn, but allow speakers to capture what exactly an object is or how it relates to others by slapping multiple nouns onto each other.
My pushchair wheel lock mechanism is broken.
Or my pushchairwheellockmechanism is broken.
Yes, the spaces make it easier to distinguish the individual components, but on the flip side it makes it much harder to figure out where the compound group ends. Even your examples illustrate that.
Different languages have evolved according to different, sometimes diametrical opposite goals. As a consequence, somethings are easier to express in some languages than in others. That's the beauty.
I'm learning Danish, and regularly have trouble working out where compound words should be divided. I can't see any benefit compared to separating the words with hyphens or spaces. The pronunciation would be the same.
English would be a more-useful global language — in that it'd be easier for non-native speakers to learn and use it — if we pedants who secretly look down on anything less than "proper" spelling and grammar (and I'm embarrassed to be one of them) would get over ourselves and accept simpler, easier forms as they naturally arise.
EXAMPLE: Less vs. fewer — it's disconcerting to read or hear, e.g., less and less people when the supposedly-correct form is fewer and fewer people; there's no logical reason that the former shouldn't do double duty, as it does in math.
EXAMPLE: Who vs. whom.
EXAMPLE: It's vs. its.
EXAMPLE: Different forms for the subjunctive — e.g., if I was a carpenter (supposedly-incorrect) vs. if I were a carpenter.