Here are some questions:

1) Should "Critical Strike" be renamed to "Elven Luck"?
2) Should "Ethereal Luck" be renamed to "Dwarven Luck"?

Considering that these skills are available to all races.

Added 6 minutes later
3) "Secret Operations" - any better ideas?
Pillage + penalty -1 to the enemy hero's speed in battle

Uncover Secrets -> Eagle Eye
Communications -> Efficiency (+1 to initiative)
Dark Weakness -> Weakness of Darkness
Bestowing Wrath -> Righteous Wrath
Endurance -> Master of Strength (+1 to all stats for each point in Strength)
Secrets of the Voice -> Voice Training (originally: Developing a Shout, confusion with a skill)

Questionable:
Witch's Reward -> Master of Magic?
Graduate -> Master of Knowledge?
(because the skills give +2 for each point in a specific school of magic, i.e., key skills for leveling up several schools of magic).