My Hangout contacts are on the right hand side and I'd like to move it back to the left and preferably hide it. I don't mind if people call me now and then but I don't need to see who's on line or not.
Given that you say you want to move it back to the left, I’ll assume that you are referring to Hangouts in Gmail. Regarding the right-hand side placement, you probably enabled a Gmail Labs feature called Right-side chat. To disable it, simply go to Gmail → Settings → Labs → scroll to Right-side chat → select Disable → scroll to the bottom of the page → click Save Changes.
As for showing/hiding it, see this answer.
To mute the notification,First you need to open the google hangout page by clicking from system tray or on the browser top.you can make use of the down arrow on the top of the hangout page.Once you click on it,you can see the Notifications menu where you can able to mute the notification.
For moving to top side of the windows,there is an option called more option on the bottom of the hangout page itself .Once you clicked on it.It would open the pop up asking for the position of the hangout on the top side,you need to uncheck it so that it would be displayed on the top side of the window.