I'm of two minds. This is a heroic, slightly over-the-top setting with energy swords, energy pistols, starships travelling/crossing distances faster than light...
1) Yep, and in that setting, dual wielding is only seen a couple of times. Even Ahsoka starts with one lightsaber, only adopting two as she grows up.
Now, how could this be treated differently?
If anyone tried to use two weapons without the appropriate talent what should the penalty be? Should it be possible at all? Or would a talent introduce the increased difficulty and advantage/triumph mechanic for a secondary hit? Would subsequent talents be two-weapon versions of other damage giving talents, just boosting the potential secondary hit?
2) Without Talents I'd say it has no mechanical effect...that would be my concession, because I actually feel you'd be at a disadvantage. You could still have fun with it, say, using Coercion to appear to be more bad-ash that you really are.
3) A gunslinger talent tree might let you get a mechanical bonus for 10 points, similar to the current rules except starting at 3 setback dice instead of the upgraded difficulty. Subsequent Talents (15, 20) would let you reduce this to 2 and 1 setback dice. It would never go lower than 1 setback die.
1) ... Meh. I think this is a mighty thin argument. But hey, different gamers different preferences.
2) I disagree. The difficulty increase, the addition of another difficulty die, is a considerable disadvantage for most characters, until later in the game at least (unless it's a one-trick pony). At least that is what my players' experience is so far, the benefit does not outweigh the inherent disadvantage of adding another die to the pool. I agree that wielding two weapons could get a boost die to Coercion check, but also setback dice to charm/negotiate checks.
3) You see, this is where I think it becomes too tier-based, too d20fied. First, and now I'm being pedantic, setback dice are environmental, external factors that affect the inherent, or what did Jay call it? Agnostic? I don't remember... the inherent difficulty of the check. So this is a thin argument perhaps, but on that alone I'd say that adding setback dice to using two weapons is wrong, because the difficulty should be based upon the inherent difficulty of wielding two weapons, not wielding one and happen to have second waving around like wind, or rain, or darkness, or uneven footing, etc... I'd say that wielding two weapons, in addition to increasing the difficulty as per the rules, could easily warrant the addition of more setback dice from other factors, such as uneven footing or darkness or whatnot, if it can be rationalised at least... Second, I think having so many talents, for so little gain and benefit is a poor suggestion. It's costly too, particularly since the gain is so poor.