Runes and classes

Ok my primary proffesion is warrior and my secondary is mesmer could I use mesmer runes on my armor dispite it is my secondary proffesion or am i just allowed to use my primary proffesion runes. And also if I craft armor is it customized for me or can i trade it to the other players so they can use it.

You can use whatever rune you like. But I think you can use only 1 rune per profession - so you could have 1 Sword rune, 1 Domination rune, and a rune of Vigor for example.
Also armor is always customized so you can only ever buy it from crafters.

€: I stand corrected.

you can only use runes of your primary profession

and armor is customized for you, therefore you cant make a set of whatever armor and pass it along~

EDIT
concerning the runes, muplite runes of the same attribute dont stack. ie: 3 minor runes doesnt not give you 3 points in whatever attribute

You can only use runes of your primary profession, and other players can't use your armor. It is indeed customized for you if you first aquired it.