It would seem to me, at least, that they are. I've got a few weapons with the highest elemental skill attribute, and even when used against enemies that are weak against that type of element, they all do less damage than a good ol' heavy attack, and with less accuracy to boot.
The only usefulness I've gotten out of them is using it against Pan-Arms and Death Gunners when they're in "invincible" mode.
Am I missing something?
Well it's been a while since i've posted, so hi guys!!!
Down to your elemental problem, it really depends on your atp. the atp the higher the damage caused by the elemental attack. The elements are good, because i was testing out my tempest striker with my FO. on the mines lv and managed to cause more damage than my regular attacks as well as "Shocking" the enemy. So elements do have their use on weapons although i would suggest that their best used with FO's.
So they're basically something that only really benefit forces? Does MST have any bearing over the damage they do?
Not absolutley. There are many exp stealing wepaons too, which can be quite usefull. And if you don't have good accuracy. or hit on the wepaon, it's useless but it still depends on the element.
Do you mean any element in particular?
Well, I'm just referring to the elemental special attacks (fire, ice, and lightning), not just special attacks in general.

well, I've noticed that sometimes it seems to do nothing at all, but there have been other times when I noticed myself doing more damage to an enemy that is weak against that element... but it could be because my current character doesnt have like uber atp yet
Elemental weapons are best used for characters with low atp, + storm weaponsare best cos they cause shock to gillchichs! Funny!!!

Yes, also technique weapons can be usefull for androids since they can't casy any. (i.e. Fire Daggers, or specials weapons such as Twin Blaze)