> "I read the docs" uses what is generally called the "plain form" (the name describes the form, not the meaning that calls for the form), and it expresses that the verb is stative[1], describing a fact about the subject ("I am the kind of person who reads the docs") rather than describing an event that takes place at a particular time.
"Perfect" was the wrong word for what I meant, you're right. I was referring to the difference between the continuous form and the plain form, which doesn't exist in many other languages. For example, in French, "je lis les docs" can mean either "I am reading the docs" or "I read the docs (in general)". My point is, even though a native English speaker (or anyone past B1 or so) understands the difference between these two phrases, many foreign speakers actually don't, and would use them more or less interchangeably, relying on context.
Lots of grammar is like this: it helps reduce the amount of context necessary, but it's not critical to text comprehension. If you speak French while using the wrong genders for nouns, people will still understand exactly what you mean - it will just sound strange and maybe make certain complex phrases more confusing than they're used to. This happens very commonly when a language is picked up as a lingua franca by many foreign speakers.
> This is very commonly asserted, but I don't believe it's true. Here you can see a popular American sitcom making a series of jokes about tone, even though the same people who will tell you that Chinese is difficult because of its tones will also tell you that English doesn't have them
Tone exists in all human communication, but it is used very differently in tonal languages. In almost all non-tonal languages, a rising tone indicates a question, a flat tone indicates a statement, and certain other tones indicate the mood of the speaker.
But in a tonal language, particularly one with absolute tones like Mandarin Chinese, tones are more similar to vowels, consonants, or stress accent: they are an intrinsic part of words or syllables. The difference between "mā" (high tone) and "má" (rising tone) is not one of intention, they are simply two completely unrelated syllables/words (the first means "mother", the second means "numb"). There are three more words that use what would be the same syllable in a non-tonal language (transliterated as mà, falling tone, mǎ, falling then rising tone, and ma, neutral tone).
Even worse, moving from a neutral tone syllable to a high tone syllable may sound like, which to a Mandarin Chinese speaker would be equivalent to moving between a syalble using "a" to one using "e" would be interpreted as a rising tone (and thus a question) by a non-tonal language speaker.