Seeing as tho a few of us have the same set up i might be able to answer.
the dash surround itself does not have to be cut, however behind that does, on the right hand side only, to allow the button side of the screen to fit. its more or less just take out the width of the screen + 5mm to allow for movement to get it right.
The screen itself comes with a bracket the is adjustable, and double sided tape. For me it was trial and error of sticking it down, the replacing the surround and having a look, did this a few times till i got it right. once it was fine i screwed the bracket down to the original plastic with a few wafers. not pretty by any means, but covered up so who cares.
Once set up the remote does not need to be used. but on mine i drilled out a small hole in the side of the surround that allows the remote to work at an angle if needed.
The lilliput screen does not have a auto reverse sensing input to switch over. i hear other touchscreens do. but im sure there is hardware/programs out there that can make this possible. brightness can be adjusted via the remote. but once again when set right, centrafuse also has a seperate button that dims the screen in 3 settings for dark night driving.
geez my fingers are sore.