This is a feedback forum for helping people get published. Getting published nearly always requires good grammar and correct writing style. Believe me, from both ends, I know. If you want my help getting published, I'm here to help.
If you can't get published but prefer to feel good about the way you already write, talk to MMI. See? Something for everyone.
This is bafflegab. Anyone can pick out a fringe rule and mention that "experts don't know" the answer, and therefore try to invalidate an entire field. But any field of knowledge worth studying has fringes with fuzzy answers. Get over it. The rules I'm giving here are well in the middle of the parts that there's no doubt about.English grammar is a joy, when it isn't confusing. But who can help being confused when even the best linguists don't know whether the posessive 's is an inflection or a clitic.
More bafflegab. Pronouns don't have an apostrophe. Except when they do. Live with it. "one's" as a possessive takes an apostrophe to distinguish it from "ones", the plural of "one". Any complex group of rules has exceptions, and natural languages are, um, no exception. Doesn't mean you throw up your hands the first time someone quotes an exception at you.And why should the word one take 's in the posessive when the rule is that pronouns do not have an apostrophe?
Confused?