The Arch skills are only available to players who have arched (seyan, sorc, warr, AT, AH).
Arch Quest Items are
Ammy from Mountains
Ice Axe from Emme cave
Rep Pot from Valley of Death (VoD)
Lisanthius Flower from Forbidden cave
Arch skills and the quest items are
Surround Hit 2 (SH2) - Ice Axe
Dual Wield (DW) - Ammy
Curse 2 (C2) - Ice Axe
Blast 2 (B2) - Ammy
Poison (P) - Flower
Compulse (C) - Rep Pot
Harden (H) - Rep Pot
Arch Quest Areas
VoD is via the Grave Yard (NE of Market) Maj Gen Skeles
Mountains is via Black Stronghold (NE of Forest) Maj Gen Barbarians
Emme Cave is via Lizard Temple (West of Forest) Maj Gen Lizards
Forbidden Cave via town (East from Cursed Tomb) Major Tarantulas and traps
New skills are available to anyone who can reach them but would be difficult even in a group before officer. Quests are via the Flower Garden via the Smugglers cave via Lancelot Village
New Skills
Shield
Wand
Staff
New professions (subject of a different forum topic) available via the Harvest areas via Prospect Peak (Major seyan protects quest item)
Harvester
Craftsman
Black Smith
Alchemist
Holding Cells and Prison Cells are noble areas and are accessible via the VoD.
I hope that helps.