Commando was my first character in SWTOR and leveling in PVE is fantastic, PVP on the other hand is somewhat of a challenge but very rewarding at times. Obviously as a ranged dps, your goal is to pump out as much damage at the 30m and then kite as needed when enemies come closer. Currently level 73 Valor on my commando and yes you will get focused more than others, but I look at this way, as a gunnery spec my Grav Round armor debuff is nasty against other players, Boltstorm will slow enemies down, Electronet will slow enemies as well with some damage, then finally the Demo Round that can bring the pain.
Now with 4.0 commandos/mercs now have another utility, Adhesive Supplements/Sticky Mods!, Power Shot/Charged Bolts and Tracer Missile/Grav Round slow their target by 40% for 6 seconds. Being able to slow down your enemies even more with an ability you use regularly is a fantastic. In addition with the new 60+ skill, Rocket Out/Propulsion Round! Jet/Fire, which launches yourself backward 20 meters, gaining immunity to controlling effects while jetting/launched, downside is that we cannot be used while immobilized or hindered. If we would be able to use the Propulsion Round even when we are immobilized or hindered, then we would finally have another way to break away when we are getting focused.
Edit: With Hydraulic Overrides/Hold the Line’s cooldown has been increased to 45 seconds (up from 30), it does pose more a challenge since other classes have gotten skills that allow them to be more mobile than they are already.
Overall I'm very commfortable with my commando and knowing all my skills and when to use them correctly is a must to survive in the Warzones. While I agree that defensively in PVP we have to be much more careful than others, but let me say one final thing. To all those that focus on us Commandos, bring it, cause otherwise we will melt you !