Hello Heartbraker,
I just looked into your three new files and you could try this:
rename > db/faction_tables/unlocked_factions
Then the table doesn't replace the IS factions table.
For the multiplayer issue copy your file to a new name and try to change the "pack-type" from "mod" to "patch".
"mod-pack-type" files don't get loaded for MP, but "patch-pack" type do. Probably both multiplayer users need to have the same file...
I have to test that with AUM 2.3 too.
Cheers
Swiss Halberdier