A:AnswerSomething is off-level. Your home's foundation could've shifted over time, which may require the use of shims to adjust. (<$2 at home improvement store).
Using a good level would be beneficial in this case.
A:AnswerMine is in a corner so I am unable to get an exact measurement but I would estimate less than 4" when closed. If planned to use closed I would recommend using a flat wall mount with no extension to save on cost.
A:AnswerAs long as you are not using the fireplace I would recommend not to. At first might be ok but over time the heat from the fireplace will weaken the mount. I would say its your call on this one for now.
A:AnswerYou should be able to make this mount work on any surface. If your going into an uneven stone surface? You can use
Tap-Conn ( brand name ) screws and use washers between bracket & wall to get it square. Might need 2 on one screw and 3 or four on another. I've done it few times never had a problem.