If you want to be a writer, you must do two things above all others: read a lot and write a lot. There’s no way around these two things that I’m aware of, no shortcut.
If you expect to succeed as a writer, rudeness should be the second-to-least of your concerns. The least of all should be polite society and what it expects. If you intend to write as truthfully as you can, your days as a member of polite society are numbered, anyway.