ive heard after patch 1.4 you can kill all the immortal npc's that u couldnt kill before, not sure is this is true tho, can anyone confirm?.

If you mean the "essential" npc's then no you can't. I can understand why ulfric and the like can't be killed but it's disappointing that the stormcloak captains at the camps can't be killed.
I want to kill them for their armor so i don't have to do the quests to get it

yeah sorry essential npcs is what i meant, thats quite disappointing to hear i hate slaughtering a whole town as a werewolf, to have 5 guys still alive because there unkillable, i would love the idea of being able to kill eveything, even if i might screw up the main quest, just seems more fun to me.

I always wanted to kill that racist [censored] in Windheld - Rolff Stone-Fist - but he's apparently involved in one of the radiant - i.e. random - quests so I can't kill his stupid ass.

Rolff is essential because if you kill him you make his brother Galmar hate you forever and, because he's aggressive, he'll always try to kill you, which can seriously screw up the Stormcloak questline.

If you want Stormcloak Officer armor, there's a man outside Forelhorst wearing it. You can kill him for it, but you'll forfeit his quest, or you can pickpocket it off of him if you have the "Perfect Touch" perk.