Once you have unlocked a skill, rune or item mod ingame, all you need to do is create a brand new PvP character, and you will have access to the unlocked skills, runes and weapon mods. Easy.
Your answer:
Create a PVP only charachter. In the PVP menu are all the things you've unlocked. These cannot be traded for money or anything, and only have acces to PvP areas ( Random Arenas, Team Arenas, Heroes Ascent, Balthazars Temple etc )
