What psychic powers do you use with these? I am having a hard time figuring out how these might be useful, as it seems to me that most psy powers would not be to effective in ship combat.

I suppose that would be Astropath Actions detailed p200 of "Into the Storm"

Or of course the new Navis Primer actions…….I believe most will use them for the astropathic teletpathy.

There's a lot you can do with your powers and an astropathic chamber, beyond what they list as options, you just have to think about it more as a stepwise plan.

Telepathy: When close to a ship, or in orbit above a planet you want to assualt (within 5VU) use Mind Scan to find a large group of people. Depending on how you rule the power use with the Astropathic Chamber (Does it increase the range from 250 Meters to 5VU?) you can then use the Mind Probe power on people to find out where the important people are, slowly tracking your foes from space until you find the person with the right passkey or information that you require. You can choose to be subtle with it or not, as it is unlikely that you'll be noticed, depending on what your mission is. This can also be useful in Ravenor style Puppet Master stuff, or even just Compel or Dominate from a distance the right person to open doors, set off alarms, attack companions, or whatever sorts of things you want them to do. Lots of utility and potential for power and profit.

Theophany: This has much utility to, from calming warp storms and shutting down warp breaches, to causing major problems for Daemon infested ships from Reavers and Chaos agents. You'd need to look, but even just being able to detect warp manifestations at 5VU can also be helpful.

As you can see, there's a lot you can do, and it works rather nicely, once you're able to get things like Dominate and Mind Scan. Hell, Reprogram from space via astropathic chamber upon the ruling class to set yourself up is just… perfectly cruel.

Okay, these have all been helpful in pointing me in the right direction.