ON DICE POOLS, SKILL CHECK, AND DIFFICULTY OF CHECKS
For those that aren't aware,
adding another green dice to your pool is almost always better than converting a green to yellow. What this means is that more dice is almost always better. The only time this isn't true is when it comes to comparing 3 yellow vs 4 green for example (in this case, 3 yellow is just a few percent better). In other situations, 1 yellow and 2 green is not as good as 4 green dice.
What this means is that probability wise, for example, is that a character with 4 green dice in a check actually has a few % better chance to succeed at a task than a character with 3 yellow and 1 green. Skill ranks are not the end all and be all of success. They allow for Triumphs, and Triumphs do not mean you succeeded, just that something good accompanied your roll.
How you should perceive your character's abilities:
Consider the below comments while remembering that an Average difficulty check is 2 purple dice, a Hard check is 3, Daunting is 4, and Formidable is 5 purple dice.
4 dice, even if they're all green, is an excellent place to be as far as considering your character good at something. 3 dice, all green means you're above average. Two green dice are simply average; making them both yellow improves the situation, but not by much.
In sum, as you consider the game and its difficulty, especially in regards to your character, you shouldn't consider your character to be really good at something unless they've got a pool of 4 green dice or 3 yellow. If you like to be thought of us really excelling at a skill or ability, then you should be going for 5 dice or 4 yellow, a place where you can reliably count on your skill to be effective.
Consider making that Hard check. Do you really want to go at it with just three green, or 1 yellow and 2 green? Or what if you're dealing with a skill check that is truly difficult, and considered Daunting at 4 purple (examples from the F&D CRB are picking a sophisticated lock or making a shot at extreme range). Throwing 4 green against 4 purple is a coin toss; a 51% chance of success.
Here's a dice roll probability table for those that are interested in Mechanics and increasing their odds of success, and consequently survival.
FFG Star Wars Dice Roll Probability Table
REGARDING THE GROUP, ROLES, ETC
Roles and skills that have been expertly addressed, or have been to some degree:
Keep in mind that an Average difficulty skill check is 2 purple dice.
Lissewa (played by Squeek) is social skill oriented, a manipulator. Full of Charm and a Negotiator of some talent. Anything related to Presence she has fairly well covered with a 4. She's also got a 3 Agility and Intellect, making her above average in those skills. A decent shot with a blaster, she also brings a droid to the party.
As a side note: Squeek, don't think of her as being good at Deception, given the above comments on skill checks. 2 yellow is only slightly above average, and getting caught in a lie is usually bad. Keep in mind that any social interaction where you lie, even a little, will require Deception for a skill check. You can pair it with other social skills as well.
For example: lying and being charming at the same time could produce results where perhaps your lie succeeds "I've got a reservation" but you fail to sway them to like you, so you don't get that table you wanted. Another example, maybe the lie fails, but you're so charming (with a Triumph you put to good use) that, even though you didn't have a reservation, they'll let you in.
Again, lies can be very condemning, so don't expect this to happen a lot. It's
far more likely that the failed Deception will hurt the Charm.
Hawke (played by Meribson) is your tech guy. I know he is focused on Mechanics, but really with 4 dice in Intellect, he's got everything Intellect related well-covered. Also, having taken the Soresu lightsaber form, he can carry his own weight in combat as well, with some ranks in Reflect as well as Parry, supported by his laminate armor. A durable type helps make a good medic, a role he capable of (Medicine), given the proper supplies or a first aid kit of some kind.
Tajanna (played by Tefmon) is bringing Cunning to the group, with a 4. Perceptive, Streetwise. A Survivor, capable of tracking others down. Good at lying over covering her tracks with Deception (? - I haven't seen anything that indicates gender, sorry if I'm wrong). Skullduggery lets her handle some locks and security measures (depending, as some electronic/complex security measures require Skullduggery, Computers, or Mechanics, or a combination of the three... some things are really hard to break into, which teamwork can help overcome). Having taken the Shien lightsaber form, (s)he uses 4 dice with Cunning for combat, making him/her no slouch given that the added Reflect and Parry as well.
Lexi (played by Dramasailor) brings a 5 Agility. Top notch pilot, in a starship or a speeder. A crack shot with any ranged weapon or gunnery system. Supremely Coordinated. Extremely Stealthy. Her 3 Willpower also lends itself to being intimidating (Coercion) Vigilant, and Disciplined (used for many force applications like Move, Influenc, etc; when in doubt, Discipline is often the go to Skill for using the force). Having learned the Ataru lightaber form, she uses 5 dice via her Agility for lightsaber attacks (potentially 6 if she increases her Agility via the Enhance force power). Combined with some Reflect she is quite capable in combat.