@benjamjensen Features 1 to 3 are not supported by TripleA which makes no provision for limited intelligence. Supporting limited intelligence would require major changes in the engine. You would probably be better off with Civilization series or the soon to be re-released The Operational Art of War.
For that matter "free for all" can be easily done in TripleA (there are many already) but they are thoroughly unrealistic. Real wars have alliances.
There are also plenty of board games that handle limited intelligence well. Pretty much any "Block" game handles this. The simple WW2 game Fog of War link text is easy to learn, fast-playing and covers the issues you wanted.