[Andrés]

The blank galaxy problem seems to appear when you attempt to load a game started without the new racial trait or as it’s been suggested here without restarting the game after making the changes.
Another good idea is to give the mod directory (you’re using a mod directory, right? It’s not advisable to change the standard data dir.) it’s own “empires” and “savegame” subdirs so you don’t mix files meant to be used by “incompatible” Versions.
BTW David your Romulan plasma weapons sound like a good addition for the Sci-Fi Crossover mod we’re making. We could use your help.