here are the weapons in the game and some info on them.
Blaster: Dash's weapon of choice, the blaster is fast, decently powerful and has unlimited ammo. I use this weapon through the level itself, and use special weapons on bosses (except the AT-ST, he's not that hard.) and other sticky situations.
seeker: Your first special weapon, it shoots a powerful missle that homes in on the enemy and hits him. However, seekers cannot home in on bosses so watch it. you can fire it at an intersection to home in on an enemy waiting to ambush you. This and slow moving enemies like Wampas and Dianogas are the only times you should use your seeker camera, as while it looks cool, you can't move and can be attacked.
Pulse Cannon: This rapid fire weapon is one of my favorites. while it isn't all that accurate, it fires rapid laser balls that can devestate slow, large enemies. Try spraying it around so enemies will have a tougher time dodging it.
Flamethrower: This firey weapon is very powerful, but slow and has limited range. Try using it on large clumps of stormtroopers or other enemies. Not recommened on enemies you don't want to get close to.
Disruptor: This is your most powerful weapon you've got. It shoots a ball that makes a big explosion on impact that is good on tought bosses. You aren't immune to the explosion so don't fire it in a narrow, closed in spot.
Stunner: Stuns all humaniod lifeforms in the room, such as troopers. Useful when surrounded by troopers, useless against droids and other non human things.