So I've been working on some "class" builds and I thought I'd share them with you:
Trait: Beserker. For my playstyle I find this to be the best trait for me. Use whatever trait works best for you though
Weapon: DLT-19 or A289C. I prefer these as a support role as they can lay down a great volume of fire and maintain reasonable accuracy at full auto which allows you to suppress enemies at a longer range.
Playstyle: Use the minimap to locate large groups of allies and follow behind them. Use your blaster to provide suppressing fire or to help focus an enemy. I find the DLT-19 is good if you prefer a more heavy weapons role and are reasonably certain of your allies ability to survive. The DLT-19 is good but you won't get far if the rest of the squad gets wiped out. The A280C is good in the "heavy weapons" role due to it's large magazine size allowing similar suppressing fire capabilities. It's better suited for situations where you may need to hold the line until allies arrive.
Dioxis grenade is used to either flush enemies out of cover, weaken a defensive position, or keep enemies from overwhelming a position. I used this to great success in a match of turning point recently where tactical use of the dioxis grenade allowed me to prevent the Rebels from being within the capture radius without taking significant damage.
Bacta Bomb is used to either heal allies or as a reserve medical treatment for yourself. It can overheal you and I recommend using it over Adrenaline stim when there's a lull in the action as it doesn't require charges.
Adrenaline Stim: used for emergency healing where you need to hold the line. You can fire at the enemy, duck behind cover to heal back to full, and then open fire again. It lasts for several seconds so this can mean the difference between holding off an entire assault wave or falling after taking down only 2 of them. While behind cover healing combines well with Bacta Bomb if you have allies that can use healing.
I choose the Beserker trait because the heals you have allow you to essentially nullify the slow healing drawback and be fully healed between firefights while having a damage boost if you get injured during a firefight. The DLT-19 gets damage on par with an A280c with the trait and the A280c gets even more powerful. While weapons like the E-11 get an even greater damage boost the focus on this build is volume of fire on the assumption you're facing multiple enemies. Other traits like Bodyguard or Survivalist would also be viable. Scout may be of less use since you'll ideally be following a squad of troops and not doing much flanking.
Adrenaline Stim (can be swapped for another card if you prefer but I like this for the enhanced survivability it gives)
Essentially this is the set up for when you aren't sure what you'll be facing. Ion grenade to attack droids, shields, and vehicles with Bacta Bomb giving you some support options.
Adrenaline Stim (Ion Shot could be used here but I personally don't find it powerful enough against vehicles to merit use over a card that enhances survival like the stim or personal shield)
Trait: Scout, Beserker
Your only focus is on taking down vehicles. Scout helps you flank them, Beserker allows you to use any damage you took killing a vehicle to enhance your weapon damage to deal with infantry supporting the vehicle. Best for modes like Walker Assault.
Thermal Detonator/Impact Grenade (personal preference between the two)
Adrenaline Stim/Explosive Shot (either increased survivability between gunfights or better damage during gunfights)
Scattergun (deals with droids, turrets, and shields; better than Ion Grenade as you can't kill yourself in close quarters with it)
Weapon: E-11, T-21 (essentially you want a weapon that does high damage per shot so that even if you fall you'll have heavily damaged the enemy). Depending on the map/mode pistols might also be viable options.
Trait: Beserker, Scout (if you prefer flanking), Bodyguard, or possibly Bounty Hunter.
As the name implies your job is to assault infantry positions or lead counter assaults. You need a weapon that does a lot of damage per shot so that any enemy left standing is severely wounded and easier for allies to kill. As this build lacks my support build's ability to heal and suppress enemies (the E-11 and T-21 fire too slow for that; the grenades lack the area denial abilities of dioxis) you have less of an ability to hold the line all by yourself you should try to work as part of a group. You won't do much good breaking through enemy lines if you don't have allies behind you to exploit the break through.