There will be no S O L O. A 'Party Leader" means just that. You will not be soloing titan ex etc etc. If they allowed solo, the 'MMO' goes *poof* and all you have left is a sword shooter. How they have progressed with this game so far has been great, and the expansion will offer even more consider the shambles this game was in 1.0

However, like any game they can still 'SCREW UP' to the point where the game becomes unrecoverable from a player base standpoint. I would assume that lower party members means 2-3 out of 4 or 4+ out of 8 etc. If they allowed solo content (Dungeons) at this stage and it offered experience points for new jobs etc while it might seem awesome cause you could spam the first room over and over you would be left with an empty shell of Astro, DRK and Mach Zombies running around.. not to mention a 'Zombie state of an MMO'