Nonpsionic characters can use any psionic item except power stones, dorjes, crystal capacitors, and a very few Universal Items (such as Eyes of Vampiric Powerleech, Skin of the Psion, Third Eye of Absorption).
Nonpsionic characters can use most weapons (except the 'feeder and psychic weapons), all armors, all skins except for the Skin of the Psion, Crystal Anchors, etc.