Q&A for How to Change Your Computer's Name on a Mac

Go to System Preferences. Go to Security & Privacy (gray house icon). Click on "Change Password..." Don't type anything in the "Old Password". Enter your new password in "New Password". Verify it by re-entering it. A password hint will show up. Choose your hint. Then click "Change Password".

You can't do that because it would involve all the directories of every file being changed to the new home folder. Your best bet would be to back-up your data, create another account, and then install all the backed up files on the new account.

You would have to go into the Settings and log out of that user's account. Afterward, you would need to remove the account and then log into your new account.

Find the F10 button on top of the numbers, and press it once to mute the Mac.

Yes. Open up your system preferences. Click the sharing folder. Go to the third row down entitled "Internet & Wireless." Find the current name and change it.