A: Right out of the box, you can't. And most security guidelines say you shouldn't.
What you're asking for is the ability to use Secure Shell (SSH) to connect directly to an ESX server's Service Console, login as root, and manage the server with your administrative credentials. You're used to doing that in Windows, but in the UNIX world, root is intended only for limited use.
That's why the standard procedure is to log on to your ESX server's Service Console as someone else and use the sudo command to run specific commands that require root privileges. Sometimes, when you have lots of commands to run, you can elevate your privileges to root using the "su –" command and the root password.
This separation helps protect you against an errant keystroke that accidentally causes catastrophic damage to your ESX environment. Being a command line-based UI, you can see how just a few characters in the wrong place can do that.
If you insist on having the ability to log on as root, you can enable root logons by editing the /etc/ssh/sshd_config file using your favorite text editor, such as nano or vi. Look for the line that says PermitRootLogin and change its no entry to yes. Restart the sshd daemon with the command service sshd restart and you're done.