If you had to choose a new lingua franca, what language would you pick?

The whole idea behind it was radical unity, internationalism, and bringing disparate people together on equal footing. Instead of me speaking a language I've known since birth, and you speaking a language you are just capable of understanding, and both of us trying to plead our case to the government, the idea is that we would all have an auxiliary language to compliment (not replace) our mother tongues, and we would both be capable of making yourself understood equally.

Those ideals don't really jive with hard nationalism and pseudoscientific ideas around superior races

Fucked if I know 😂 I'm studying it on my own from textbooks and online resources, not in a classroom setting taught by scholars much much smarter than me. I assume the reduced complexity of simplified characters makes it more accessible though, which is why I understand the PRC makes Pinyin required on road signs as well.

This is only partially true. Very early on, this was the case - Chinese characters started as pictograms representing objects and concepts. But this was fairly limiting in how much complexity you could capture without creating an unmanageably large set of unique pictograms. So the system evolved to use compound characters (characters made up of 2 or more components) incorporating phonetic (i.e. pronunciation) information into the writing system.

Most Chinese characters used in past 2000 years are made up of parts related to their meaning or category of meaning, and parts related to the pronunciation of the spoken word they represent (at least at some point in time, typically in Old Chinese) - these are called phono-semantic compound characters. The first comprehensive dictionary of Chinese characters that was created almost 2000 years ago already classified over 80% of all characters as phono-semantic compounds. This percentage also went up over time in later dictionaries as new compound characters were still being added.

As an example the character for book (書) - is made up of 2 parts, the semantic part is 聿 (brush - in its original form a literal picture of a hand holding a brush) on top (so the word is related to writing or painting), and 者 on the bottom (the meaning of 者 is not important here (it was a picture of a mouth eating sugarcane originally, but lost this meaning long time ago), but 者 in Old Chinese was pronounced similar to the Old Chinese spoken word for book, so it serves a purely phonetic function here)

When Chinese writing was adopted in Japan, it wasn't really used to write Japanese - it was used to write Classical Chinese. Literate people would translate from Japanese to Chinese (which they would have been fluent in) and write it down in Classical Chinese grammar and vocabulary, not spoken Japanese grammar. They could also read it back and translate on the fly into spoken Japanese for Japanese speaking audience. They also brought in the Chinese pronunciation of the Characters into Japanese (in fact several different versions of this over time - see Go-on, Kan-on, etc.) so the phonetic hints in the characters were still useful when learning the system.

Attempting to write spoken Japanese using Chinese characters was difficult, initially they would actually use Chinese characters stripped of their meaning to represent Japanese syllables. These were later simplified to become modern kana

Spoken Chinese itself evolved beyond the monosyllabic written Classical Chinese (which remained quite rigid), so for a long time, Chinese also wrote essentially in a different language from how they spoke. It was only fairly recently that vernacular Chinese began to be written (rather than Classical Chinese) with it's polysyllabic words (most words in modern Chinese have 2 or more syllables, and require 2 or more characters to write, further distancing modern words from the original simple pictogram meanings)

So while the idea of some kind of universal abstract concept representation divorced from phonetics sounds intriguing, in practice it is a poor way to capture the complexity and nuance of spoken languages, and all languages (including Chinese) that attempted to adopt it ended up having to build various phonetic hints and workarounds to make the system actually useful and practical for writing.

China has an extremely high literacy rate, so the difficulty in learning the system is, at least, provably surmountable.

The strength of being able to unite communication historically across East Asia and potentially around the world is a pretty big plus. Offering such a strength impossible in other systems, ideograms are hardly equivalent to imperial units.

Isn't toki pona supposed to be an art language?

Is Esperanto similar to what you're talking about?

Bir örnek, mesela bu mesajın türkçe çevirisini, yazabilir misin?

I don't think it's as easy to see, but grammar wise it's really simple. No articles (not even a "the"), there is no concept of "definite" and "indefinite" grammar wise. Things either are defined (my house, that house) or not (any house, one house, two houses) or it doesn't matter (I'm going to house) grammar wise, no difference.

And really anything is made with suffixes, the only thing that I would consider problematic is remembering the correct order of suffixes. For example above:

çevir-i-si-ni

çevir(-mek): to turn around, exchange, translate
çevir-i: the thing that got turned around, exchanged, translated
çeviri-(s)i: the messages's (turkish) translation, a genitive construct where message has the genitive ending (-in) and the corresponding possessive suffix (-(s)i) binds them together.
çevirisi-(n)i: accusative case, relating it to "writing", i. e. write the messages turkish translation.

There are quite a few rules governing vowels and consonants in suffixes but they are highly regular. There are very few exceptions that need to be learned seperately. (and even a lot those can be turned into rules, though I suppose at some point the difference hardly matters)

Maybe wrong, but I believe this is from a language learning sub on reddit where people would ask what language they should learn without any other qualifiers. It was asked so frequently that people just started replying Uzbekistani.

Again, that's my memory of it, could be wrong.

IIRC there still are dialects. Like, a gesture exists on a continuum of possibly trajectories, and one "speaker" might do it slightly differently from another.

I have no clue, but it'll be better than a language that thinks it's acceptable for words like "read"
to not just have two different meaning, but two different pronunciations,
while also having words like "sense", "scents" and "cents" be pronounced exactly the same.

And while writing this, I just learned that pronunciation should be spelled with "u" instead of "ou".
That makes no sense.

I first heard of the expression in a fancy dinner a relative brought a diplomat she was dating, and for diplomats all around the world for the last four or five centuries French was the Lingua Franca, as well for meetings between courts, aristocrats, academics, and the first language a book would be translated to because up until a few generations ago if one wanted to learn an "international language" it would learn French, which makes the etymological assumption understandable. However I just went to check some info about it since I was just told Franca doesn't come from French... turns out, it has nothing to do with Germanic languages as well, but a mix of mostly Romance languages used through the Mediterranean for trade and that maybe got its name because Arabs, Turks, Persians, etc called all Europeans "Franks" and it was synonym of Westerner.

Then it's just a happy coincidence that it was the first world wide language used for diplomacy.