Sorry, still not quite right. A small percentage of the Chinese characters do indeed qualify as ideograms, but most are not. The Chinese writing system is logographic - each character directly represents a word - not a picture, not an idea. 90+% of the characters are formed from radical/phonetic combination: a radical (their are 214 in the traditional count, though there’s a certain fuzziness in the enumeration for reasons I don’t care to discuss) plus another, simpler character that’s used to hint at the sound of the word. The radical provides a clue as to the meaning - common ones represent people, or wood, or metal, or speech - and the phonetic part suggests the sound (though the characters were largely formed so long ago that the correspondence sometimes no longer exists.) This is a completely different principle than an ideogram, which tries to suggest at a concept using a sort of symbolic representation - for instance, a “region” enclosed by a “border”, which represents “country” or “kingdom” (guó in Mandarin Chinese.) Like I said, this is a fairly small subset of the characters. Radical-phonetic characters are not ideograms.
Further, again, “letter-based” is a nonsensical description of a language. There is no inherent coupling between a language and its writing system, and there are various different ways to write Chinese without using hanzi. If Chinese was in such a political position as to be useful as a world language, it would be, though most likely international use would use a romanization rather than hanzi.
You’re mistaking effect and cause here. English is used in virtually every country on earth, and as such it has to import foreign words. Great Britain as world-spanning empire historically imported a great number of foreign words; the United States, being one of the most culturally diverse countries on the planet (and debatably also a world-spanning empire) continues this tradition. English has more cause than most languages to import foreign words, because English-speakers, collectively, run into a lot of foreign concepts. This has nothing to do with any inherent characteristic of the language, as any language used as widely as English would by necessity do the same thing. Besides, other languages do import foreign words, in enormous numbers, and you’d be hard-pressed to prove that English does so any more than any other widely-used language. These relatively new foreign words that pop up in English are used in other languages as well. If a foreign concept becomes relevant, a word will arise to fill that need.