OpenMW is an engine replacement for Morrowind, decently done (when it comes to the game; their editor lags significantly behind) - it has some quirks and some advantages (it's the best option if you want to be able to alt-tab out of Morrowind, for instance, and in this case its world map allows scro...

The closest to indicating the Free Estates being joinable in publicly-available written stuff is the "choose sides in the loyalist-isolationist schism, and go to war against the enemy subfaction" part in the write-up above, but the Nobility Faction writeup also suggests a Hlaalu-Camonna To...