1. By default in Linux, like windows, you have at least two accounts. The administrator, called root in Linux/Unix, and the installers user account called whatever you selected when installing.
The user account in Linux can act like the root account at any time by using "sudo".(I've read a bunch of things over the years for what "sudo" stands for but I like the one "SuperUserDO".)
When you need to do something that requires the SuperUser account root you can do it with your own account by typing; sudo command any-other-extra-requirements
Have a look here; https://help.ubuntu.com/community/RootSudo
You can use "your" account to play with or create a second account just for testing things. Up to you but I usually stick with one account unless it's for work testing.
Note: In order for sudo to work you need to be part of the sudoers group which I have found doesn't always happen automatically like it did in the past.
2. If the video seems resolved we don't need to worry about xorg.conf or vi/vim. But just out of curiosity did you leave a space between; sudo cp /etc/X11/xorg.conf<SPACE>
/etc/X11/xorg.conf.mybak Although you might not have an xorg.conf file created I would expect one. The above string/command needs to be copied exactly as case matters in Linux and "x" is NOT the same as "X". What the above string means is use the SuperUser to copy a file found at /etc/X11/ called xorg.conf to a second new file named xorg.conf.mybak.
But as I said, if things are working as-is lets just back away slowly and leave it be. ;c)
3. Clock issues in Linux are usually simple enough once you set it once it's done. However using dual boot it can make things a pain as both Windows and Linux will change the time when you login to match what it believes is the correct time. Usually advancing one of the OSes hours ahead or behind.
In a terminal window in Linux type "date" without the quotes. If the date and time look alright you might need to right click on the clock on your screen so you can adjust the date and time through the GUI, Graphical User Interface. If that's the case its usually the time zone.
If the date/time is off in the terminal window you can correct it by typing; sudo date YYMMDDhhmm.ss -u Which would look like; sudo date 1301252212.23 -u
The date command uses 24hr format and you can drop the year or seconds if you wish. -u stands for setting Coordinated Universal Time.
date --help will show you all the command line switches and some explanations.
It will take a few minutes for any changes you make in the terminal window to show up in the GUI clock on your desktop so don't expect it to happen at the same time.
Let me know if this helps you at all.