I completely agree with OP. These things must get fixed as it completely ruins the experience.
I've had alot of trouble using my skills in warzones with my gunslinger. No matter how much I pust the buttons there's always a long pause before anything happens. Taking cover is probably the most frustrating thing since it takes a good while from I push my button to the character actually starts doing the command.
I can't sit around waiting 1 sec before something happens and thats more or less what it takes, for me in anycase, before my charatcer starts rolling to cover. It's not too bad with my other skills, but the cover command is really unresponsive.
Odd thing is, when I'm in the pve enviroment I don't have any problems with my cover button. Perhaps it's because I always use it before entering combat so I don't pay attention to it. It's probably still there, but it's not a major problem in pve compared to pvp.