Fast question.

I get the rules for maintaining several Powers, but what do you need to do to maintain a single Power that is maintainable?

Is it maintained automatically? Do you need to do a Focus Power Test every round?
i cant seem to find the rules about this, or am I blind?

Strange but nothing said about it in Corebook.

In Dark Heresy, you must pass a test once in 10 rounds or 1 minute for sustaining a power.

RAI, in RTrader you also lower a Psy rating by one for sustaining 1 power.

Yeah, I thought it stranged but saw in another rulebook that they are automatically maintained if u spend half an action on it

Would be nice to have that in the RT core book to though