Bioware has done a good job with classes’ abilities. They've created interesting rotations and playstyles. For me, the addition of cover classes is revolutionary and something closer to modern warfare. The feeling I have thought is that they could do better in some things. Most classes don't have enough utilities or I think they should have a more dynamic playstyles. I have some abilities I would suggest. I know that they cannot changes classes midgame but they could surely change some with an expansion.
For Warriors/Knights both AC:
Disarm. 90sec CD. Cho mai is used a lot by both Jedi and Sith. It would last for 12sec and it would prevent abilities that require a weapon.
Force Deflection. 30sec CD, last for 6 secs, the Jedi/Sith uses the Force to defend an attack and reflect it back to the attacker.
Battle Prowess. 120sec CD. For 12sec you deal and receive 20% more damage, you are allowed to use Vicious Throw/Dispatch during the duration and you are immune to slows and throwbacks.
Cower in Fear. 60sec CD. Incapacitate your opponent for 60sec/8scs in PvP. Effect breaks if any damage is dealt after 2secs.
Chasing Throw. 20sec CD. Throws your main hand lighsaber, doing little damage, increase your speed by 30% for 4secs.
Both classes should have disarm abilities that are popular in SW universe and movies. Plus, the reflect ability is something that is also used by the Jedi in the movies when they deflect back their enemies weapon blasts. Now, a big dps CD is missing in Juggernauts/Knights dps rotation that's why I believe Battle Prowess will come in hand. Finally, a Marauder/Sentinel has enough dps but lack in Crowd Controls. Another stun will help them kite and survive better than what they have now. As Juggernauts/Knights have more mobility I believe Marauders could get a small sprint.
For Inquisitors/Consulars both AC:
Battle Meditation. 180sec CD. Increases the party's damage and healing done by 15%. For me, Battle Meditation is the most iconic Force ability in the Old Republic era and would make many people happy if it's implanted.
Force Mark. 120sec CD. Marks an opponent for 30sec. Every time that the marked opponent receives damage from the Sorcerer/Sage, heals up to 3 allies standing in 15meters for 30% of the damage from the marked opponent takes. If an ally is marked then any heal he receives from Sorcerer/Sage, damage up to 3 enemies standing in 15 meters for 30% of the healing done to the marked ally.
Force Slow. 40sec CD. Any enemy inflicted by this ability has his next channeled or casting ability used after 6sec to have it's time to activate increased by 100%.
Dreadmaster. Strikes fear in the enemy, causing him to cower in fear for up to 20 sec. Damage caused may interrupt the effect. Only 1 target can be feared at a time.
Shatterpoint. 240sec CD. Increase your abilities critical chance by 40% for 12sec.
Precognition. 180sec CD. You are immune to all damage for 8sec. You also do 50% less damage.
Battle meditation is an ability that I was surprised that didn't make it to the game. Especially when there's only one advance class with the ability to increase the performance of a group. For me, Inquisitors/Consulars are the most polished and all-around class and they don't need a big change. Force Mark is a very interesting ability as it’ll give a twist that is needed in a mmo. Force Slow gives a strong weapon against healers and other ranged dps. Assassins/Shadows are in need of a big dps CD. Also, fear fits into sorcs/sages. Shatterpoint is also a very interesting Force Power in the SW universe that could fit in the Assassins/Shadows story, as the seeker of Force knowledge. Same goes for Precognition. A strong defensive CD, mostly for the assassins dpsers than the tank. In general, the SW universe has very interesting Force Powers that could spice up the force users gameplay.
For Imperial Agents/Smugglers both AC:
Carefull Shot. 90sec CD. Disarms the opponent for 12secs. A really, really good ability that is missing right now.
Duty Calls. 180sec CD. Whenever you are attacked by an enemy your moving speed is increased by 4% for 12sec. It can stack up to 5 times.
Erradicate. 180sec CD. Attempts to break the damage reduction shields and all invulnerabilities. Needs to be in cover.
Tactital Superiority. 120sec CD. For the next 6sec all of your abilities don't consume the Tactical Advantage buff.
Cloaking Area. 180sec CD. Creates a an Invisible Area in 10m around the Operative/Scoundrel for 6sec. Enemies are confused and can't target into or out of the cloaking area.
Emergency Countermeasures. 180sec CD. Decrease the CD of all of your abilities by 50%.
Sniper's Patience. After remaining stationary for 4sec you get sniper's patience that increases your next Snipe or Ambush critical chance by 3%. Stacks up to 5 times.
Master Marksman. 120sec CD. For the next 20sec it allows the Sniper to shoot Snipe out of cover and while you are moving. Every Snipe that is shot consumes a Sniper's Patience buff. Any melee attack you receive has a 50% chance to restore a Sniper's Patience buff. This effect cannot occur more than once every 6sec.
IA/Smuggler should have a Disarm ability, a defensive CD needed in game. As class with no sprint, no charge and with little mobility a small moving speed buff is needed. Operatives/Scoundrels got nerf when their burst was reduced. Right now it's a class that has little chance in a head on against most melees and ranged. Eradicate will break the defense of their opponent, forcing them against a wall. Tactical Superiority will help them hit harder against kiting opponents. Snipers/Gunslingers are a class of area denial, where they can protect their spot pretty easily. The problem is when they'll get force to battle in close quarters. Sniper's Patience and Master Marksman will give Snipers/Gunslingers the chance to kite, to maintain their range against melee. Also, a stationary covered Sniper that is an upper level, cannot be charged, cannot get countered from Warriors/Knights. Give Snipers mobility and give Warriors the chance to land on them.
For Bounty Hunters/Trooper both AC:
Gravity Generator. 30sec CD. Places a gravity generator that pulls all enemies up to 15m to its center. Then it slows them for 50% until they leave the generator’s range.
Carbonite Shell. 180sec CD. You create a carbonite shell around you that makes you invulnerable to any damage. Lasts for 6sec.
Repelling Shield. 45sec CD. You use your shield to absorb an attack of an enemy and in the next 6sec you can unleash it back to an opponent.
Matter Transmitter. Place at your feet the exit of a matter transmitter device. After that, every 40sec you can use a second matter transmitter and enter into the hoop that it's created and be transmitted to the exit.
Warmachine. 21sec CD. 20m range. Fires a barrage of missiles that explode on contact, doing high damage and increasing all damage dealt for 15% for the next 9sec. The missiles can hit the target even if the enemy is not in line of sight.
Armor of Retribution. 60sec CD. The heat of your armor burns every enemy that attacks you in melee range for 30sec.
Cold Blood. 60 sec CD. Powertech gains his calm and rally his allies removing all Fear and Disorient effects from party and ops member. This ability can be used even when the user is afflicted with such effects.
Bounty Hunters/Troopers are in a very interesting spot in my opinion. Heavy geared, can take a beating... Really, really like them. They still need some more dynamic playstyle. Gravity Generator is a nice crowd control ability that can be follow by Death from Above/Mortar Volley. Carbonite Shell will give a big defensive CD that would mostly help the dps than healers or tanks. Mercs and Commandos are quite good right now. They lack mobility as Arsenal/Gunnery and even though they get some in Pyrotech/Assault Specialist, they lose some dps. Instead of giving more instant abilities I suggest Matter Transmitter. Same goes for Warmachine that would be a nice and unique ability. Totally worth against fleeing enemies that try to hide behind a crate to heal themselves up. Right now, mercs/commandos feel like a stationary turret. Even if it's intended, I believe that it would be fun to give them some kite ability. Powertechs on the other hand are extremely well designed. Great mobility, lots and lots of abilities the only thing I came up with is a dot against melee and a CD to remove fear to give them some more fast paced action.
In general there are many interesting abilities but are not equally scattered. For example Marauders/Sentinels seem to be more interesting than Juggernauts/Guardians dps, especially in PvP. Marauders/Sentinels get a healing debuff, a sort vanish and stealth, a health regeneration and finally a major dps increase, whereas Juggs/Guardians only have an extra charge to their allies, a temporary increase of health and a defensive cooldown. I hope my suggestion would mostly instigate of a more all around abilities, with more mobility and versability. DPS rotations are mostly fine and with the changes in AoE heals I'm mostly happy with the healer experiences so far.