I don't like something in the FAQ/I think something is missing in the FAQ, can I propose a change or a new addition to it?
How do I make sure it gets official? Are there standard procedures?
Of course you can!
This is not a dictatorship, the site is being ruled by everyone, so you can propose a new change and try to include it in our official FAQ.
How do you do that?
It's simple: ask a new Meta question tagging it feature-request and faq-proposed. In this question, you'll need to ask the community what they think of your proposal. When you gain enough attention and a good number of people will agree with you, then a moderator will tag your question status-completed and it will be included in the FAQ.
If you need further elaboration fo your idea, you can still use your question or, better yet, partecipate in our monthly Chat Meetings, also inviting your fellow users to support you in the discussion.