As for two different ways of saying 'the', I assume you mean 'thee' and 'the', and if so I think it's down to dialect. I have never said 'thee' except when reading 'Olde Worlde' English...
The choice between "the (with schwa)" and "the (with long 'e')" is like the choice between "a" and "an" - the choice is determined by the initial sound of the following word, with the first option for words starting with consonant sounds, and the second for those starting with vowel sounds. I specify "sounds", because in English the long "u" starts with a palatal approximant, which is classed as a consonant - thus words like "uterus" use the consonant version of the articles, not the vowel version.
(Also, "the" actually has a third variant, used only before words starting with a long "e" sound - in this case, "the" ends with a glottal stop.)
A person yelling "Fuck you" in a crowd in English. As you say, no one knows exactly who is being spoken to. This is because of ambiguity, something that English is full of. It's completely ambiguous who the object is, or even whether the object is plural or singular. How can you state that this "communicates an idea simpler and quicker than in Spanish"? In Spanish you instantly know, at least, that the person is talking to (for example) one person instead of a group of people. That is more information because of less ambiguity. In my book Spanish wins.
Every language has ambiguity - and every language has means to clarify that ambiguity when needed. For example, nouns in Japanese are ambiguous in regards to number and definiteness - "hon", for example, can refer to a book, a specific book, several books, a specific collection of books, or books in general - verbs are not inflected for person or number, and pronouns are optional; even a simple, ordinary statement like "hon o yomimasu" (literally "book read") is utterly indecipherable when taken out of context. But there are many ways to clarify if needed: "anata-tachi wa takusan hon o yomimasu" "you (plural) read many books", "ashita kanojo wa kono hon o yomimasu" "tomorrow she will this book", "watashi wa ano kawabyoushi no hon o yomimasu" "I'm reading that leather-bound book over there".
The thing is, oftentimes these ambiguities aren't even important to resolve - they only seem that way because we're used to having to make those distinctions. For example, you notice the ambiguity of "you" far more than a native English-speaker does, because you're coming from a language where making the distinction between singular-you and plural-you is obligatory. That ambiguous Japanese sentence above, "hon o yomimasu", is absolutely unambiguous about one thing, that neither of us would even think to notice because it's not a grammatical feature in English or Spanish: the relative status of the speaker and the listener. There are languages that distinguish between inclusive-we (first-person plural, including the listener) and exclusive-we (first-person plural, does not include the listener) - to people who grow up speaking those languages, "we" and "nosotros" are ambiguous in ways we can't even imagine.
The rule is, as I said, clear and consistent. It also conveys more information that the English equivalent. If I say "I dropped the plates" a listener needs to inquire further to find out whether I dropped them on purpose or whether it was a mistake. This is immediately clear in Spanish.
Which seems perfectly natural to you, because your first language obligated you to make that clear. To an English speaker, who's language does not force him to make that distinction, it doesn't seem important - and if we feel it is, we always have the option of saying "I accidentally dropped the plates" or "I deliberately dropped the plates" (or even "I threw the plates to the ground"), while still being able to say merely "I dropped the plates" if we feel that the plates' having been dropped is more important than whether or not it was an accident. That's the benefit of ambiguity like this - it gives you the option of omitting unimportant or irrelevant information.
Just like the distinction between definite and indefinite as exemplified by the/el versus a/un seems perfectly natural to us, but seems totally unnecessary to a Russian (since Russian has no articles, definite or indefinite), who would also be amused at our insistence on using the copula (be/ser) in sentences like "I am a student" "Soy un estudiante" when he can simply say "Я студент" (literally, "me student").
Spanish is also a somewhat strict language as far as its rules go. For example, every vowel in Spanish has one sound. It is always pronounced that way, and once you learn how to pronounce it you always know how to pronounce it. If you look at a word written in Spanish, and if you know a few rules, you immediately know exactly how to pronounce that word. There are very few exceptions to any rule. English, on the other hand, is flooded (to use your terminology) with exceptions to absolutely every single rule.
Spanish spelling is relatively young, focused on a single dialect (Spanish spelling is based fundamentally on Castillian pronunciation), and uses an writing system derived from a language - Latin - that Spanish is itself descended from. English spelling, on the other hand, is about a century and a half older, incorporates spellings from a wide variety of disparate dialects, developed in a time during which the English language was changing significantly, and uses a writing system derived from a language - again, Latin - with a very different phonology.
Spanish has 20 consonant and 5 vowel phonemes, which works quite well with an alphabet of 26 characters, with most of those characters retaining the same pronunciation they had in Latin. That same alphabet is not as good a fit with English's 24 consonant and 14 vowel phonemes.
Think about the way you pronounce the following words: thought, enough, though, cough, bough. Each one is a different pronunciation of the "ough" pattern. How the hell do you teach that to someone?
There are relatively few words with the "-ough-" sequence - it's not that much to simply memorize the more important ones.
500 years ago, all those "-ough-"s were pronounced the same. Subsequent language evolution has caused them to diverge - and the spellings are gradually being replaced as a result. "Hiccough" and "hough" have been replaced by the now-standard "hiccup" and "hock"; "plow" and "draft" are already standard in North America, and "naught" is now standard in the US; and "thru" and "tho" are now acceptable in informal American English.
Language changes readily, but orthography does not
How about.. if someone says "bite", do you spell it "bite", "byte", or "bight"? How do you know? Seen, scene, feet, feat, etc.
Those examples, at least, are easy to determine from context.
What about silent letters? How do you know how to pronouce "gnaw" if you see it? If you hear it, how do you know how to spell it?
Fact is that English is one of the hardest languages to learn in the world. That's because it's an unstructured mishmash of languages from vastly different etymological lines. What makes it the "best language in the world?" Nothing, the reason everyone learns it is that the English colonization effort was very widespread and successful, and after that there was the rise of the USA as the dominant superpower. Well that's on the way out, and quickly, and soon everyone will be signing up for Mandarin and you'll only hear English at your local Beijing McDonalds.
Correction: English is one of the harder languages to learn to read and write
. Learning to speak and understand it is no harder, and possibly even easier, than most other languages - it has a relatively large number of phonemes (but by no means the largest), has a lot of consonant clusters (which are forbidden in most languages; though again, nothing approaching the monstrous consonant clusters of a language like Georgian), and makes finer tense/aspect distinctions than many other languages, but on the other hand, nouns and verbs have very few forms (roughly four each, with the notable exception of "be"), the overwhelming majority of verbs and nouns are perfectly regular with only a single inflection pardigm for each, most irregulars are only irregular in one or two forms, adjectives are not inflected at all, there's no grammatical gender except for third-person singular pronouns, there are no tones, there are relatively few exotic phonemes (it does have an abnormally large inventory of fricatives, but no retroflexes, no clicks, no ejectives or implosives, no laryngeals, no vowels that are only distinguished by lip-rounding), there are no complex consonant mutations (like in the Celtic languages), there are no grammaticalized evidential markers (like in many Amerind languages) or respect/status markers (like in Japanese), and there are relatively few person/number distinctions.
As far as Mandarin becoming the global lingua franca
, suffice it to say that, like all Chinese languages, it's tonal. Tones are almost impossible to acquire for people who did not grow up speaking a tonal language - which is most people. And Mandarin is even harder to learn to read and write than English is. An inventory of several thousand characters, with well over a thousand needed for basic literacy, with the phonemic content of each character based on pronunciations that are 2000 years out of date, with many compounds being unpredictable or downright opaque, and with simplification having obscured the phonetic and semantic components of many characters. ('telephone' = 电 'electricity' + 话 'talk', not 远 'far' + 话 'talk' like a European would expect; 电 'electricity' + 车'wheel' = 'streetcar', not 'train', as the cognate compound in Japanese can also mean, and certainly not 'electric car', which is 电动车 'electricity' + 'move' + 'wheel'. 电 is the simplified version of 電, which is composed of semantic 雨 'rain' and phonetic 申 /shen/ i.e. rhymes with /shen/ and has to do with rain i.e. /dian/ 'lightning' - 2000 years of language evolution having blunted the rhyme - while the simplified version is just 田 /tian/ 'field' with one stroke lengthened. And absolutely none of this helps you when writing.)