For the HQ, you should definatly get a Crisis Suit Shas'El or Shas'O. IMHO, they are way better then Ethereals, although much higher in points. The added BS, WS and Leadership can really come in handy. Of course, the Ethereal is also essential, as he keeps your Tau from running far far away once the battle get ugly.
For your Fire Warriors, I'd drop those 5 carbines in the squads, as you dramatically reduce your firing range. The best thing about Fire Warriors is the Pulse Rifle, with the 30" range. With the carbines, you only get 5 shots per squad, but if you had only 2 carbines, you'd get at least 8, while still retaining the pinning capability of the carbines if the enemy gets too close.
Although some people aren't a fan of Kroot, I would strongly recommend a squad. You may not use them in every game, but the counter-assault and assault delaying elements of them can be invaluable.
Otherwise, it loks good.