Connor MacLeod wrote:True, although if that's the case why haven't they tried already? The Tau know what psykers are and use them (They used them to scan the minds of non-tau/human recruits in "kill team") and they would almost certainly have to be aware of how humanity uses Psykers (astrophaths and battle psykers, the latter which IIRC they haven't bothered with either.)
It's unlikely they trust a non-Tau race with their communications, when their courier ships are effective enough to be practical at present.
There's also the little matter of whether they have an analogue to soul binding (which IIRC is a key bit to astropaths and sanctioned psykers and the like) - if they started using them this way I'd have to wonder at the risks of corruption and whatnot.
Soul binding is necessary for run of the mill human psykers. However, the lack of the Nicassar being possessed by chaos already indicates that they're comparatively stable, like the eldar, better human psykers, squat psykers, krork weirdboyz, and so forth.
This also presumes they have any sort of telepathy. from the way the Nicassar are described the TK abilities they have are more a specialized, innate "required" power (its how they move.) If they are telepathic, this does not neccesarily mean they're strong enough to provide the sort of communication astropaths do (IIRC Astropaths are a very particular degree/kind of psyker.)
Not at all. Astropaths are most of the human psykers that don't get eaten by the Emperor. It's fairly basic, even if the training isn't.
Something tells me they either tried and its failed (for now) or they just lack what is required for astrophathic communication (power, training, etc.) Same for any sort of "sanctioned psyker/battle psyker" analogue.
They've not had the time or inclination to develop a system of astropaths. They're likely in for more nasty surprises if they try.
They can also already navigate through the warp via warp gates (Kill Team), so they could arguably enter and navigate the warp in theory, but for some reason they don't seem to use this very often.
Without the navigator gene, it would give them very little advantage. Presumably the Ork trait of getting where they want to go is something gestalt, while it might work for Kroot, it may not be practical for Tau. And without that, there's little advantage in 'full immersion' compared to their existing drives - both peter out after four light years, and the former comes with much greater risks
Well the beacon network is an obvious limitation, since it limits them to established routes and can be something the Imperium or others could easily hamper.
In any case, even if they DID develop a Navigator analogue, they probably wouldn't be able to travel any great distances without an astronomicon equivalent (or by being able to use the Astronomicon itself.) - IIRC not even the Eldar have an easy time navigating the warp for any great distances the way Navigators do (they're limited to fairly short-distance jumps too and have to use the Webway for fast long range travel.)
The eldar are also likely short range because they attract demons like a flourescent bulb attracts moths and flies. Orks, in comparison, do have a navigator analogue, somehow.
In terms of the Nicassar, we don't know if they can function as navigators - they certainly don't navigate on their own (and the Tau haven't bothered or even seem to have tried using them in that way yet.)
Tau drives aren't as bad as people think. While developing a full warp drive would be trivial, as I said, developing a navigator replacement... really wouldn't. There's a mini-story in Xenology about another race attempting to subvert Navigators. The Imperium immediately reacts to anyone it finds doing that... badly.