I only want one thing, and one thing only, for you to focus on. Optimize this engine. Optimize it to run on 400/500 series cards. Optimize it to run on quad core cpus. Optimize it to use 4gb+ of ram. Optimize meshes, geometry, and ai. It's all you need to do. Do this and the modding community can fix everything else wrong with this game. Optimize the engine and we can load hi-res texture. Optimize the engine and we can add mods which will tax the cpu. Optimize this engine and half of everyone's issues will go away and the other half modders can fix. This is the only thing, THE Only Thing the modding community cannot fix. We can fix the bugs, the glitches, hell, someone could probably even fix the issues the game has with large saves, but the engine is what you need to do so that the modding community will actually be able to make quality mods.
This is really what needs to be done. It's just BS that my OC'd GTX 570 is dipping below 40 fps with only some 2048 landscape textures, at 5 grids, with 250+MBs of free vram. Pft, even fully vanilla, on utlra, fps can dip to 30 in certain areas. It goes without saying that the shadows in this game are downright terrible, no doubt something that only tweaking the engine could fix.
OPTIMIZE THIS ENGINE!