1. https://www.shamimsplugins.com/docs/front-end-pm-pro/getting-started-2/translate/
2. You can go to front end pm page (from where user send message, you can also send from there)
3. https://www.shamimsplugins.com/docs/front-end-pm/customization/remove-minlength-message-title/
Please let me know if you have any more question.