I fancy explosives, a lot. Even with my non engeneers, I am prone to using EZ-Trhow and EZ-Trhow II. A warlock may not appreciate Dynamite as much as a class with no or rediclous (read low dammage huge cooldown)AoE, for example a druid(no hurrcane dosent count as AoE, it just stinks)loves Dynamite.
The issue is you are doing something wrong, unless you are fighing mobs way over your level, like 5 levels, you shouldnt have issues with range that is unless you are trying to get the part of the target icon closest to you on top of the mob(I just center the disk on mob and let it loose). With all that in mind rember that explosives work best when you have a tank, Hey Warlocks have one of those, use it to hold the mobs while you throw.
Lets move on, up untill now i have spoke about Dynamite exclusivly, and while a lil AoE dammage is nice, as a engeneer, you can use better than just explosives wraped in cloth, you can use Bombs and grenades, the diffrence is those types of explosives usualy carry a mild stun with the dammaging blaze( and the dammage is usualy better).
The last thing to keep in mind is the level of your explosive vs the level of the mobs, if you are hanging arround level 24-28 mobs chucking Rough Copper Bombs at them wont help much but a Big Bronze Bomb will set the stage for a few moments of dazed mobs so you can get your next attack in place.