[Mossy Toes]

The ITC faq (unofficial faq adopted by most tournaments, these days) rules that a psyker can only get one primaris free; that having powers from 2 schools (even if one is the forced primaris) means you aren't eligible for a second free primaris.

It is a gray area in the wording though, definitely! It comes down to consensus and how your local group does it, honestly, I think. Until the ITC faq ruled it out, I definitely played my daemons that way--just made sure to check in with my opponent to make sure they were ok with it before my matches, so when my ML1 Horrors suddenly had 3 psychic powers...

 

[Mossy Toes]

The exact quote from the rules is: The number of powers they can cast is dependent on their level. HOWEVER, it never clearly states HOW it's dependent.

Well, given that a unit can only attempt to cast each power it knows once, it's limited in the number it can cast by how many it knows, I suppose.

 

[Mossy Toes]

Yup, sounds like what I was talking about with the ITC faq--depends on local standards. Good that you figured this out before whatever local events you were planning on attending!