I leveled an alliance lock on Darrowshire and made it to R8. A typical matchup for me vs an UD rogue is he opens up, I seduce, he uses WOTF, I death coil, then grenade when it expires into a fear. Obviously several factors and cooldowns need to be available but that's the best shot for you outside of engineering and other sweet trinkets such as tidal charm, arena master, jungle remedy so you can CoE kite etc.
If there's a gear disparity you can just mash cooldowns and/or drain tank with the voidwalker in case you need to sac. Basically utilize anything that will give you the edge and reserve them specifically for UD rogues or whatever other class is your bane. Warlocks can do insane burst also if you're conflag spec and if the stars align with a NF proc as well so try to use that to your advantage. SL spec gives you a ridiculous amount of survivability in bg's which works out very well against just about all melee and casters who refuse/can not dispel so if all else fails your best course of action may be to do that. Goodluck!