Forgeworld is always good about answering questions from it's community regarding rules, updates, and problems that come up. Here are a couple questions and answers regarding Imperial Knights for the Questoris Lists, and Daemonkin in IA 13.
Imperial Knights
I was talking about bringing in the new Knights GW is creating for 40K into the Questoris Knights list.
as far as I am aware there are no plans to do this at the current time. Though We never know exactly what the studio is going to spring on us at any given time!
Daemonkin
I'm not sure if this has been addressed, but I did receive confirmation of IA13 in use with the Daemonkin Codex.
We will no doubt publish an FAQ at some point in the future to cover new Codex releases such as the Daemonkin but in the meantime you can certainly use any of our models from IA13 in your Daemonkin army as part of an Unbound force and most definitely in a regular force if your gaming group are happy for you to do so in a ‘House Rule’ environment. In terms of where these units would fit in to the Force Organisation we recommend treating it as a Chaos Daemons Codex.
If you plan on using some our Chaos units in a tournament or event then we recommend contacting the event organisers for any clarifications but we are certainly happy for you to use them there.