not as bad as it could have been
I agree with Walink. it could be really good, but you need to do a little more reasearch before you continue the series. here are a feqw mistakes I noticed:
The vessels: The tau ship looked more like a space marine frigate than a custodian. and they would take an Orca dropship down, not a devifish. you can find pictures of these on the FORGEWORLD website.
The space marines were pretty good but they are way more vigilant than that
Mon'tau means, the terror, Its Tau'va that means greater good
The Infantry: The Tau have hooves, not feet. you also gave them too many fingers. they use names like shas'el' shas'ui, shas'ar'tol RATHER than captain and general, not as well as. you should use their given name too, eg La'Kais (quote from game fire warrior). the pulse rifle blasts were pretty poor. commanders go in crisis battle suits, not on foot.
Not bad for a first try. a few mistakes to correct, a bit more reasearch and you'll have a good series. by the way, please let space marines win, i collect them.