If you want to type a literal question mark or period in your text, you can say it just like in english "you want to go to the park question mark" becomes "you want to go to the park?"
however it will also try to auto detect punctuation, just like english, if you say nothing about it. this is based on your over all phrases and pauses, to varying success.
As someone else mentioned, the most difficult thing is actually getting the literal word "question mark" typed, in chinese or english. The computer really can't comprehend the context between a command to it and a word in the message, the ai isn't so advanced.
I don't think there is a solution for the third scenario in phone keyboards like gboard. However I'll note that if you had a proper diction program on a computer they are heavily trainable and editable to match the individual voice and habits unique to the user, and you could definitely teach it two different commands, one each for the symbol "?" and the vocab "question mark" etc.