I think speed system works like this:
Movement speed and action speed are separate. Fleet footed grants you a bonus to movement speed, but the quick trait only affects other actions like firing weapons, melee combat, picking up and dropping stuff, probably taking medications/eating+drinking as well as filling containers. I think crafting times is fixed, and reading time can only be reduced with fast reader trait.
-encumberance on feet and legs gives bonus to movement speed. +encumbarance gives a penalty
-Adrenaline rush gives a bonus to movement speed
-some stimulants and alcohol give bonus to movement speed
-Pain greatly reduces your movement speed
About arm guards, every item can be wielded and used as a weapon. That’s why clothing has horrible Bash values, it is not an effective weapon. The number of moves to attack is the swing speed of the weapon. 100 is an equivalent of walking with regular movement speed on the regular terrain. Fx. a Sledgehammer has attack speed of over 200, which means that every time you swing the enemy is most likely to hit you twice or thrice (with regular attack speed). Once again, every item has this value, but you won’t use every item as a weapon, so only focus on those numbers if you are planning to use the item as a weapon.
For clothing focus on encumberance, coverage, warmth, storage, protection values and volume if you are planning to remove the clothing before combat.
I hope this makes sense, and feel free to correct me if I’m wrong.