Nah, you wouldn't believe the possibilities it opens up when clearing neutral creatures... Though, for single-player, it's questionable.
She's a decent hero ;)
Regarding Faiz, it would be good to enhance the ability (increase the damage of the Beam) and add a specialization for Djinns (since he has Darkness, they learned from him how to cast random spells).
Added 4 minutes later
I'm also curious which heroes people consider completely useless from the standard set, so we can send them to the chopping block? ))