The dragonsworn armour is the pretty much the same as the 5th slot armour we got a few years back , you need a broken dragonsworn armour/weapon drop for each piece , these drop from dragonsworn mobs.
The bonuses are here
Ehrayn's New Crafted Armor Bonuses Cheat Sheet
Mists is a repeatable lvl 40 quest that gives roughly , 1.8-2.1 bubbles of exp per run ,
Allakhazam.com: Dark Age of Camelot
Yar is part of the dragon quests , hes part of the quest chain to get the dragonslayer armour/weapon.
Big 3 is the dragonslayer quest for your dragonslayer weapon , you dont have to purchase the dragonbane weapon to get credit.
Allakhazam.com: Dark Age of Camelot
Lotm is a rvr dungeon based underneath agramon heres a basic guide
Classes of Camelot - Labyrinth Overview , it also enables cl6-10 and the ability to use mythirian items.