One of the side benefits of working on this game is we have a totally real justification for playing through it ourselves. We play twice a week at lunchtime. We learn a lot about not only mechanics, but also how different people play and organize themselves.
We completed Rise of the Runelords when we were a smaller team. Our loadout included Harsk the Tracker, Amari the Berserker, and Ezren the Illusionist ("I'm an illusionist, Michael..."). Now that we have a larger team, we've started anew with Skull & Shackles. It is great for getting everyone understanding how flexible we need to make our game rules. We just finished the first scenario (0.1). Our crew is a bit nuts but covers all of the bases, Lem, Oloch, Damiel, Seltyiel, Lirianne and of course Ranzak (played by yours truly).
I personally have a solitaire 4-character Skull and Shackles game going at home which has taught me a lot about what kind of interface a player will need to track a lot of characters. In that game, I'm running Damiel, Seltyiel, Alahazra, and Jirelle.