Failed my search roll on this, so forgive me if it was answered before

Sustaining psychic powers section covers only sustaining 2 or more powers at once, but at least in my understanding ( my english could be rusty ), says nothing about sustaining one power, and using another 'instant' one. For example - librarian is sustaining Inspire, and try to cast Smite/channel power through force weapon etc. Is his PR reduced for both powers, only for sustained/casted, or not at all?

And another - RF on psychic powers - errata states, that it's possible and calls for another, exactly the same Focus power test. Does Deathwatch training works on this? And what in case of opposed WP test - like using force weapon, Blood boil etc.

1. RAW non-sustained powers have no side-effect and can be cast normally if you can pay the action cost. That's how I read it.
2. I would say DW training does work. It's a roll to confirm RF.
3. I would rule that you just roll against the same adjusted WP value as before. Enemy WP does not factor into it, just as dodging doesn't figure into a normal attack's conformation roll.

Alex