Help with WHM securing

Let's start I get recently a vps managed, i could get with root access but i choice without root access Questions 1 - With root access I'm able to do more functions "have more power" tell me why? When i order my product, ask to use a domain, i use my primary domain, the domain i will develop my project. I setup few information on my whm and... Questions 2 - The password for my domain cpanel is the same as whm, any chance in have both totally different? 3 - Any possible to change/block or hide some entries on my domain DNS like (whm.site.com / cpanel.site.com / webmail.site.com ....) ? Looks unsafe Also if you are free to resume or link me some content about make things more secure, gonna be a nice idea too. Thank you J