- as long as there is not multiple ways to pronounce what you have written in the context it is in, it should be fine. Also, even in english and other languages sometimes numbers are included in the form of for example “thirtieth place” instead of “30th place”, or “the war started in nineteen thirty eight” in place of “the war started in 1938”
- Do I understand that those take place of English
!?.,, or are similar in their intent? In that case I would probably include them, anyone who uses the data can strip them, or try to even use them for I don’t know, determining how speakers usually indicate presence of those? - just choose whatever length you find suitable, and better shorter than longer. If in doubt, try pronouncing the sentence, and keep in mind people tend to stutter so may take longer to read than you
- no idea, someone else will have to input on that