All good advice.
Expect the tech questions to be relevant to turboprops, plus the odd 'I did it during my ATPLs and forgot all about it' type question, just for fun.
Such as:
Decode a TAF or METAR, plus follow-up questions (e.g. would you land in these conditions?)
What does a yaw damper do?
Why do we have propellers at max rpm for take-off and landing?
What is the service ceiling of the Q400, and why?
And my favourite:
What is the difference between IAS, CAS, EAS & TAS?
Don't get too worked up over the technical questions - you can't possibly be expected to know everything, and the interviewers are fairly gentle. I suspect they are much more interested in what you are like as a person.