No, it's not that. No need to make my day. I understand it till where you get to the spelling itch. It may be that you and people who think like you do not need punctuation. Or hardly any.
I only mentioned punctuation again because the sentence I quoted gave me troubles reading it. First I had to look up no-brainer, which if you do not know the word can have two meanings.
I checked if it meant 'dumb' (having no brains) but it proved to mean 'simple' (no brains needed). I run over the sentence a few times and now assume it means that it is hard for you to conjure up a context in which spelling and punctuation have to do with grammar. (is that right?)
Maybe an extra comma would not have been much help.
I like you examples although I do not see why
"2. The current King of France is bold" isn't logic, but that just a detail.
I need punctuation in written texts that are not poetry or literature. To me it's like a reinforcement of the structure.
You do not need it. Whether it is part of grammar I cannot say because I'm no linguist. No language expert. I have from my language education always accepted spelling and punctuation as belonging to grammar.
Maybe I'm wrong.
