The lightning element deactivates Deidara's clay for good, we can see this in Sasuke Vs Deidara fight. Where Sasuke uses Chidori senbon to deactivate Deidara's small clay bombs and they don't go off.
And yep, I do agree that the fight was not up to the expected mark, but I think we're looking at it from wrong end. What I'm trying to say is we're expecting too much from the revived member's just because they're once powerful when they're alive.
Also, as someone pointed out, it is not necessary that when a soul is revived it retains same power (ps: I'm saying power and not ability) as the original. Meaning, even though the revived ppl may retain their skills the body used as a sacrifice to tie down their soul to living world should be powerful enough to perform various jutsus and handle the backlash if any due to said jutsu.
About Sasori not being emotional when he was alive, that guy converted his whole freaking body into a puppet, how can we expect him to feel any emotion. Also, when he is defeated by Sakura, he does inform her about his meeting with a spy amongst Orochimaru's ranks. Here we can for sure say that he did feel something towards the end of his life which made him to reveal this information as he was not obliged to do so in any way.