Also this might help
http://www.bay12forums.com/smf/index.php?topic=136126.0The dwarven compendium. Nice glossy pdf explaining the armour and layering (amongst other things) in different words to ther wiki. Cross referencing between both and playing the game might be helpful.
Its been said but for the purposes of not getting nakedness unhappy thoughts, the minimum requirement is chest leg and foot coverage. Ropes covering the chest (and possessing greater coverage than a shirt - which is what I usually use for chest coverage).
As you say MeMyselfAndI if u only make mail shirts and metal high boots, their civillian clothing trousers will rot off, so I would suggest metal leggings to go with mail shirts and high boots. If you go that far I think it would be remiss not to add a helmet (as DF skulls are interestingly modelled and result in a higher casualty rate with plumb strikes than other body parts) and since gauntlets are probably low weight (im assuming), I add those too (speaking for all citizens that dont mine or hunt).
There is a lot of anecdotal evidence from adventure mode posters that multiple cloaks (6 i think is the max with a mail shirt(s) can sometimes avert a blow. I
think cloaks also protect the face, which helmets dont. I think the face has a low probability of being hit. There are masks and facemasks, veils and headscarfs too but I think dwarves cannot natively produce those. My understanding is that because cloaks are made out of relatively weak materials when compared with metal armour, ie cloth and leather (lets not discuss candy cloaks) that they will often be penetrated anyway. I tend to try and make all my military grade clothing out of leather, just in case leather is marginally tougher than cloth if I go to the trouble of adding cloaks, socks (actually not leather socks cause you cant) mittens etc to my standard "whole metal coverage".
Also with regards to clothing quality, from the wiki it is suggested that masterwork armour has a higher deflection rate than anything less. Coupling that with the fact that a cloak
can deflect a blow to the face ive got to say that I beleive a masterwork cloak is probably more protective than a non masterwork
I personally find the layering and UPSTEP LBSTEP etc a bit confusing. It doesnt seem right that a character should be able to wear 6 mail shirts and doing so has ramifications for other areas, so I just go with single layer metal armour (usually steel) and fairly skilled dwarves are pretty untouchable in melee. Missile fire is another matter.
Yeah armouring all the civillians could be considered exploity, if we had a better UI and methods for controling/protecting/deffending I would be less likely to do it, and I dread the day when metal armour wears out. I hope we can repair stuff rather than having to continually replace metal armour. I armour all the civillians more so they dont die from a random raider when cutting wood outside my walls. Its quite a bit of work as well to actually get all the civillians armoured up so I feel like the reward of not having to continually replace clothing is a sort of pay off for good military practice. Not to mention the miners and hunters cant do their jobs with armour on. (I hope the latest version has changed that but ive got my doubts and havent tested yet).