This topic came up ages ago.... Basically, some of our weapons say 'attacks struck by the sword grant x' while others say 'the sword gives the character x'.
It is my conclusion RAW that the weapons of the first type definitely cannot benefit the maiming shield effect. For example, our old friend blade of realities only effects blows struck by the sword, so no extra attack that can autokill. However, the second type, and I've forgotten names but I believe the one that includes granting flaming attacks, says they give the ability to the bearer, thus he would pass it on since it becomes part of his basic stats. It only says the attack must be at base strength, not everything else at base.
But its definitely a grey patch and could be argued either way.