If you think slingers and smiters have a damage problem, the fix is not give both the possibility of +20 damage (at cost of two more feats availabe even if you're not a fighter), only when a XR is unlocked.
This. Unfortunately, we are discussing subraces here, not (needed) class edits
This this. As to BKs, the promised spell edits are going in, and some statting tweaks will help to ensure more use from bigby's in upcoming runs. Is the 'help' they need a descendent of an old bigby nerf, or more? This should probably be broken out into its own topic.
Likewise, I'm going to suggest a topic for each of these subraces. Take a look at what poli did for Half-Shiradi - makes it very easy to assess consequences of edits.