Hey Faith!
Thanks for using WP Job Manager! I’ll answer these one-by-one for you:
1. Depending on your settings, users will have to be logged in to post a job. You can configure this setting under Job Listings > Settings > Job Submission – setting.
2. You can definitely remove it from the menu, by going to Appearance > Menus and creating a custom menu that doesn’t have it. Another cool thing you could do is only show the link to logged in users, by using a plugin like Nav Menu Roles.
3. It’s technically a WordPress login/registration. The users are the same as ‘WordPress’ users, but you can optionally configure under the WP Job Manager settings to give users a certain ‘role’ when registering through the form, like Employer, that may give them different privileges. They are still a normal WordPress user though.
I hope this helps you out! 🙂