You could take and eliminate all the extraneous visual elements, but the experience window's pretty central to the UI. In Profit it's got a lot of the code that handles things like class/subclass detection needed by all the other bits of Profit. It's also got a lot of behavior hard-wired in by the game, and eliminating those parts of it will cause the game to reject the window completely as not compatible. And since the game considers that window mandatory, having it not work will probably give the UI system major heartburn. Long and short, you probably could do it but it'll be a lot of work to get the graphical elements removed without breaking any of the scripting and dynamic data and other non-visual parts of the window.
"Hey! I'm not illiterate. I had a book once. ...could've used some ketchup though..."