Warlocks are definitely a support class, they are the kings and queens of AoE (area of effect). the general job of a warlock is to deal with "mobs" or "ads" these are the large groups of enemies that run into the fight. you'll want to use your vortex grenade or nova bomb to deal with these groups when they're bunched up, this will really up your kill rate and make the battles alot easier. You'll also want to master the glide ability, it gets alot better when you upgrade it for better control. You should use it to get from vantage point A to B and to gtfo away from enemies. It takes a bit to master but once you get it down it becomes a fundamental part of playing a warlock. This means learning the right times to descend or make a shot and then glide again. Harnessing your low health but high regen in battle you'll need to be ducking in and out of cover. You do some damage, quickly hide, glide over to another vantage point, mid glide throw your grenade or time a shot to descend, land where you want, rinse and repeat as the situation needs. You don't want your health getting into the red because this will drastically slow your regen time and you'll have to hide for longer and may miss out on moments you can take advantage of. The warlock is the scholar, you're smarter than everyone else, watch the battle, blend with it and control its flow. Also make the most of your slide and the ability to jump and reload at the same time, it's extremely useful for you.