Just a couple of quick ideas regarding channellers:

Maybe a "focus" skill of some sort which is checked
whenever you drain a room containing deposits etc
or rooms which have a very high 'drainage' value.
If successful you focus some of the channeled energy
and create a small crystaline orb which could then
be used for future craft orb skills.
Cant sell to shop, break if dropped.

Could possibly then also have orb storage containers
to store crafted orbs, similar to the pouches for
reagents and boxes for minerals...
Maybe "A small/big/huge leather satchel" or somesuch.
Hideously expensive from the guild shop, of course