Well, I have to confess the possible new direction of the Beta has encouraged me to start trying out some of the rules in my current Only War game. I've decided to start by trying out the Social Interaction rules.
The first thing I noticed is that Servants of the Imperium seem to be less well disposed to starting characters than generally indifferent people. According to the rules, a loyal Servant of the Imperial has a Disposition equal to the highest Influence among the PCs... but, if I understand the rules correctly, a starting character might have a maxed out Influence of 45. A totally indifferent NPC would have a Disposition of 40-60... so a loyal Servant of he Imperium, helping someone he knows to be an agent of the Inquisition would be on the low end of indifferent to him? That doesn't sound right.
Another thing I noticed is that the effects of Social Skill use on Disposition seem odd and a bit confusing. A successful Charm test on a Submissive person makes them less well disposed to you? A failed Interrogate test on an Aggressive person makes him better disposed to you?
I think it might be easier if there was just one rule for the effect of Social Skills on Disposition, for example +5 Disposition per DoS, -5 Disposition per DoF. Personalities determine the modifiers to the skills but success improves your chances and failure makes them worse.
Finally, I'd love to see an example personality of Suspicious, since I think that covers a lot of people an Acolyte might be talking to.