Seth can be easily killed by casting Poison Cloud repeatedly near him, but not directly targeting him (so he doesn't turn hostile and attack). Of course there isn't much point to playing on hardcore if you are going to use exploits like that.
In the disk version of the game scorpions are fairly over powered. That was fixed in the download version, but I'm not sure how effective they are there.
There are 5 pieces of dragon armour: a shield (Rivertown), belt (Verdistis), Gloves (Dark Forest), Breastplate (Verdistis) and Helm (Dark Forest). The last two can only be gotten after you have completed the dwarven council member quest; the first 3 can be found whenever you reach the area they are located.Dragon Armour Quests