Pick your allowed conventional commit types and any custom rules, and the tool outputs a commitlint.config.js ready to wire into a commit-msg hook.
Yes. Install husky (or similar) and wire commitlint --edit $1 into a commit-msg hook so this config is actually enforced on every commit.
Yes, as a starting point — review names, paths, and details against your actual project before committing.
No. Everything is built client-side in your browser; nothing is sent anywhere until you commit it yourself.