However, aren't Qt and similar systems for rendering windows and widgets in the OS desktop environment, not for rendering them inside a game's render area, like on the console or inside a fullscreen graphics display using OpenGL, SDL, etc.? So it would seem that to use them would require extensive recoding of their render system, no? Seems that'd take an extraordinary amount of work.
Also, I've noticed that I'm still not sure as to how to do the rendering system in general. Should one just have one big "renderer" object that takes in maps, dialog widgets, text messages, "stats" info (i.e. player's HP, etc.) etc. and renders them to the screen?