Astropathic Choir-Chamber - What Powers work with it?

By BlackSpike, in Rogue Trader Rules Questions

A Choir-Chamber adds 5VU to the range of an Astropath's powers.

This should allow them to use their powers during Ship combat (assuming the ships are close enough).

Which powers could this be used for?

How does targeting work?

e.g. Can I Mind-Probe an Enemy Rogue-Trader to know his tactics?

Can I Mind Scream their Gunner?

Do i need to Mind Scan first, to locate/identify Minds?

Would Compel work?

If anyone has any insights into this, I'd love to hear them!

Our potential-astropath is wanting a Choir-Chamber for our ship so he can join in the hostilities on enemy craft, but we're not sure how it would work!