I don't know a lot about building
IG lists (seems fine though) but from a Tau perspective, you might want to *consider the following* (evoking Bill Nye):
bonding knives are generally a suboptimal use of points. This is largely due to the fact that it only comes into play in a small fraction of situations, and you'll probably be benefiting from ethereal
Ld on top of that. If you think it'll be better for your meta, give it a shot.
Fire Warrior are not super durable to begin with, but 6 man units are especially flimsy. I'd recommend bumping them up to 10 mans, for their own durability but also to help keep your ethereal alive. He needs bodies to
LOS. With this in mind, its probably best to drop a pathfinder squad in oder to bulk up your tau troops.
Your pathfinder Shas'ui isn't really bringing much to the table. You'll probably be benefiting from ethereal leadership bubble too, so i'd use the points elsewhere.
See also:
http://youtu.be/c4mpPiS523o on bonding knives
http://youtu.be/IfJGe_BPvrQ on fire warriors
http://youtu.be/gXbYiCZ2vmY on pathfinders