And there are, of course, counter-examples: el águila, el ala. I believe the rule should just be "it sounds right", as to say "la águila" is well, a third 'a' in there, two or them consecutive, and is just harder to even pronounce.

It gets worse in French: un livre (book), une livre (pound, in France equal to 0.5 kg). They're even pronounced the same.

Yes, yes, but this example is so well trod that it immediately popped into your mind, and, what's more, try to think of a sentence where you might honestly be confused about whether "pound" or "book" was meant.

I can certainly imagine a French learner being confused about which gender goes with which noun. Before you say that this is ingrained in French speakers, so are unphonetic English orthography, Chinese tones and ideographs, and other linguistic sticking points ingrained in the native speakers of those languages.

French has quite a few words that break the apparent gender rules: un musée, un lycée, un mille (meaning "mile"; the homograph meaning "thousand" is feminine but usually doesn't take an article), le mort (dead person) vs. la mort (death), etc. All adding to the shit you gotta memorize. If you don't, your meaning will still come across but you'll sound "off".

(I don't even think I remember all my Vandertramp verbs...)

Well my whole point is that it doesn't make a whole lot of sense to talk about whether one language is or isn't appropriate as an international one because the idea that one is just objectively harder than another doesn't really hold.

Le port and la port.

Port is always masculine though, it only means port/harbour.

But it's not that important, gender does add some redundancy and some error-correction to a language. It's not necessary (as shown by English) but it has some use.

I guess he's thinking of "la porte" but the pronunciation isn't the same.

That only happens with a handful of words: those that 1) are feminine and 2) their first syllable begins with an "a" and 3) their first syllable is stressed.

It's similar to English which uses "an" instead of "a", but it happens very very very rarely.

(Needless to say, "águila" and "ala" ARE feminine nouns, what's changing here is the determiner so the two a's don't clash, not the gender of the nouns)

If the last letter determines gender what's the point of using "el" or "la" at all?