Kusari is flourishing now. For both lawfuls and unlawfuls. The Kusari codex makes it available for police patrols to actually profit, so do bounties.
For unlawfuls and quasi lawfuls, there are appropriate bounties as well as piracy chances.
For the corporations there are two well established competitors who after all the day's work is done do sit together and talk about well being of Kusari as place to play.
Its true that there are always many players in Liberty (Specially in Pennsylvania and New York) but problem is, Unlike what you think, It's pretty hard to Roleplay in that house, because most of the players there are new to this game and not so good when it comes to RP.
If you ask me, you should first make an Indie char in some factions and get to know their RP, then if you want you can join the Official Faction.
Try to move out of Liberty, you can find some really good RP in Rheinland or Bretonia (Kusari is a good place to RP too, but its not as good as Bretonia or Rheinland)
If you want a faction that gives you more 'Action' you can join Police factions, Rheinland Federal Police or Bretonia Police Authority. There are not many players in Police factions (because most players go for Military factions) but still, they give you enough PvP.
If you want good amount of RP, but still some PvP, join one of the House Corporations as an Escort, many 'Trading' Factions also have ships as Escorts.
Also there are some factions that have their own Special Roleplay, unlike any other faction, which can be interesting, like Xenos, Junkers, Hogosha, Gaians, Bundschuh and Unione Corse. They are mostly Unlawful factions but are not regular Pirates like Rogues or Mollys, but if you want to try any of these factions, make sure to read Wiki page of its both NPC and Official faction before joining them, because their RP might get a bit tricky;)
Just spend a few hours reading Faction Wiki pages so you can decide on which faction(s) to join.
And if you think none of these roleplays suit you, you can always make your own Freelancer/Merc/Pirate/Vigilante char and invent your own type of Role Play!