Mo Zhu's Shortform

Yeah  - there's a huge amount of characters that are the combination of some logogram with a phonetic marker. Memorizing these is about as hard as memorizing a short English word's meaning purely from its shape if you disregard the sound.

In a vacuum, yes. But the implementation is harder. Requiring everyone to simultaneously change pronunciation and writing is more difficult than changing one or the other first. In Chinese, these two things can be separated. 

And in a vacuum, yes. But if you think a global language is worthwhile, you'd settle for pronunciation or writing first, rather than demanding both. So while it is a desirable feature of a global language, it is not a necessary feature. 

University of Lyon researchers François Pellegrino, Christophe Coupé, and Egidio Marsico didn't travel the world, nor did they survey every single language, but back in 2010, they did use the process above to determine the speech information rate of seven of the world's most spoken languages: English, French, Italian, Japanese, Spanish, Mandarin, and German.

English came out on top, but not by much. Most of languages grouped pretty closely together, however, Japanese lagged behind the rest.

Interestingly, the languages that conveyed the least amount of information per syllable, like Spanish, Japanese, and French, tended to be spoken at a faster rate. This allowed these languages (apart from Japanese) to deliver a similar amount of information compared to more meaning-dense languages like Mandarin and English.