Questions on armor mechanics

i havent played GW since 05 (hurricane katrina ) back when i quit there was only chapter 1 out at the time.

thinks i know:
Reduces damage from attacks from knights armor; 1 piece effects you no matter where you are hit but 2 pieces doesnt add to the amount that is reduced, so 1 piece is all you need
+AL (to whatever) only effects the area that the AL is covering, ie if chest has +AL and you get hit in the head the chest AL doesnt help.
Shields add +AL to you no matter where your hit (except in the back)
absorpution runes are applied everywhere so you only need 1

now when i was playing before i dont remember insignias, so im guessing they are new from ch 2 or 3. anyways if i apply Armor +10 (while holding an item) insignia does it only work on the piece of armor i put it on or is it applied everywhere? and how do i complete the condition (while holding an item)?

Knight's armor now only applies the damage reduction to the area where you are hit. Therefore, if you want the damage reduction to be global, you need a full set.

+AL still only effects the piece that it is on.

Not 100% on this, but I think the shield armor bonus has always been universal and all around (seems to be true from my farming experience).

Absorption runes still don't stack so there is no point in having multiples.

Insignia's are the answer to all the fashion conscious players. Now, when you buy an armor set, it comes with no bonuses. In order to change the 'blank' armor to a specific type, you need to apply an insignia to them (similar to how runes work). An insignia will only effect the piece of armor it is put on, so if you want a full set of a type of armor you may need 4 or 5 insignias.

As far as the (while holding an item) thing goes, it's easiest to either be a ritualist or be a ritualist secondary and use one of the ash summoning spells. While holding the ashes you'll receive the bonus and be able to cast, but won't be able to auto-attack or use warrior/ranger/paragon/assassin/dervish/anythingelseImighthavemissed attack skills.

nice info, so how many blank spots come in the armor so i can put insignias in?

Each piece of armor has one insignia slot, however you can apply a new insignia over an old one at any time you like

Every armor piece has room on it for one insignia and one rune.

which chapter is this availalbe in?

all chapters now as of about 2 weeks ago