Not directly. Wikipedia links are no follow, and their value comes from increasing your website’s trustworthiness and organic traffic.
No. Wikipedia does not sell link placement. However, you can pay for an expert to make an authoritative article and use it as a Wikipedia backlink.
No. All Wikipedia links are no follow to avoid SEO spammers.
Yes. Anyone can edit nearly any Wikipedia page. However, if moderators identify the change as malicious or unwarranted, they will revert the changes.
Yes. Wikipedia moderators will ban your Wikipedia account and add your domain to Wikipedia’s spam blacklist if they find out that your article has false information, advertising, unnecessary links, or keyword bloat.