They prog, at least. My big gripe with leader weapons, from what I remember w/ Nhiala, is that they don't exploit any vulns and are heavy. So they're sort of a niche thing.
Who gets them, anyway? Just Battle and Fort?
Battle's weapons should probably have a physical attack and do something like cause bleeding, or prog for critical hits like those ghostly ones. That seems in keeping with the theme of the cabal.
Fort weapons should probably have a searing light attack and prog for either fire (which they do now, I think) or light. Given that maran can lightforge searing light weapons, the leader weapon's physical attack makes it a poor choice when fighting duergar, orcs, or anybody with resist physical (minotaur, giants, necromancers via wraithform).
All leader weapons should be made of energy. Doesn't seem fair to drow/elves to make them mithril/iron, and having them be made from some "earthly metal" doesn't seem to fit with the fact that they have divine origin. Plus it makes them a poor choice for fighting druids and (some) invokers.
I'm fine with the way they're nodrop but not noremove. I'd make them lighter, across the board, but not so light that they're impossible to drop. I'd also make the weight depend on the current "weapon type". I've heard that, currently, when the weapon is transformed from one type to another the weight stays the same. That's silly. There is no conservation of mass for god-given fantasy weapons.
Basically, for a given weapon type, look at the array of "decently high average" weapons of that type, and pick the weight near the low end of those weapons. For sword, maybe make it 8lb or so. For dagger, 4-5lb. Staff, maybe 12lb. (Just rough numbers). 14lb daggers don't make sense.