There is no night vision button without Profit UI to my knowledge...but I could be wrong...also, in the last patch they fixed the problem with shadows being one of the main issues with lagging graphics, but depending on your graphics card... The game has very good graphics, even me running a very high end machine run the game on the one above Balanced...High Performance works well...
Note: There is a bit of messing around you need to do to get used to the game, play with the settings, and move the UI around, mess with UI settings... Like I said, it can be a bit overwhelming at first...but once you get it down, it is awesome...btw...my UI is set up similar to WoW's, you can set up options for, move, and resize ANY window in the game....