It'd really depend on what you want the character to do.
Having a super high crit multiplier is a bit crap as a rogue unless you plow everything into a flat damage bonus (Deadly aim, High str, wep spec etc) and then can consistantly get critical hits. Even with 5 attacks all of which hitting, even with improved crit doubling your threat range, you still only have under 50% to score a crit. That seems a bit wasted for me. The question to me seems, "If you want a crit heavy build, why go rogue?" Rogues' sneak damage isn't multiplied on crits, making the threat range and crit multiplier useless for the majority of your damage. Also: dumping BAB points into deadly aim means that you're losing hit which you can't really afford to gain damage which isn't huge.
Thematically, I'd probably go for standard daggers. Same damage, but twice as likely to crit - making them the best weapon for a crit reliant spec if that's how you want to build him. Plus, Daggers are a much more common weapon than a starknife, making finding upgrades that much easier.
Also Daggers could be used in the following combo: Palm shot + Sneaky shot + Critical shot. Of course, this would double your number of attacks but mean that you'd lose all Str bonuses (thanks to Palm shot), meaning that I'd just plow everything into Dex and ignore Str altogether.
I'd really run this past your DM first tbh. The class was (I assume) built around the idea that you'd only be throwing one weapon per round. With Pathfinders "Multi-throw per round" system this class would seem more than a little unballanced allowing (at max level) 7 shots which would give 14 damage rolls, all of which would have 7D6 sneak damage on them, in addition to their base damage. That seems a little high to me...