trang ouls on a non-sorceress/non-paladin

[apandapion]

What skill items will boost the fire wall on a trang ouls when worn by, say, a barbarian?  +sorc fire tree?  +fire skills?  +all skills?  all of the above?  none of the above?

Doesn't matter, anyway. I was trying to build a paladin around conviction and meteor, but it turns out there's no way to put firewall or meteor on the left mouse button, thus making it impossible to do both an aura and meteor at the same time.

Stupid interface.