As far as I've found, the hover-over faction name cant be changed (it's probably there, somewhere, but I just cant find it.)
As for the faction effects, these files are the ones you need to deal with (in both the main db tables and the text db tables):
effects_bundles - for the "Masters of..." text. It will be under "t_<clan name>"effects_bundles.loc also is needed to fully change the description of the "Masters of..." text
effects.loc - look for "effects_description_clan_trait_<clan name>". This is where you type in the trait and chose what shows up in the clan's specialties bullet points.effects - Look for "clan_trait_<clan name>". Here, you make it the same name as the one in effects.loc (minus the "effects_description_" part, obviously), then pick a priority for it. Look to similar traits that other effects give for reference. You also can change the icon that appears, but that's only really needed if you're changing the clan mon and want the effect image to match.
effects_bundles_to_effects_junctions - This is where you link up the trait in "effects" and "effects.loc" to the bundle in the previous files. So, go down and find the "t_<clan name>" and put the "clan_trait_<clan name>_<trait>" that you want with it (for as many clan traits as you have). As for the value, again, look to similar traits to judge what number should go there.
Hope that helps.