Did anyone get the in game items for the Noble, Royal and Imperial editions? They are supposed to be at Oleg's tavern in a chest if I recall, but I didn't find anything like that.

No one on GOG as far as I know.
The DLC from Premium Editions is missing on our GOG accounts. Steam users have it.
Its called 'Premium Digital Copy DLC'

Someone should contact the support and let them know.

I have Imperial edition and I found both the Red panda, Owlcat, Experts hat and Mesmerizing necklace in the chest in the Olegs fort.
As for other digital goodies, they are available under Backup & Goodies in GOG Galaxy.

Premium Digital Download includes 2 in-game items to help an aspiring adventurer (a signet that allows you to bless your party several times a day, and a belt with a bonus to disease and fatigue resistance)

Maybe a stupid question, but I will ask anyway. The "Experts hat and Mesmerizing necklace" are normal items, which are received by everybody?

In-game, bonuses:

Pre-Order bonus item
- Experts Hat,
- Mesmerizing Necklace,
- Owlcat pet

Noble / Royal / Imperial
- 2 additional portraits
- Premium Digital Download (ring and belt)

Royal / Imperial
- Red Panda

Imperial
- Season Pass

http://www.deepsilver.com/us/pathfinder-kingmaker-release-date-and-digital-editions-revealed-preorder-today/

Thanks for clarification, I was unable to find what was part of the preorder bonus, I have thought that it is just a Owlcat.
Anyway I have just filled out support ticket, but I guess we will get response next week at best.

You are welcome :)

Let us know what did support said, please. So we won't spam them with the same problem.

Ok so support responded (actually this is second response, but first response was just link to another post on this forum) and I received the missing DLC "Pathfinder: Kingmaker - Premium Digital Copy"

I have started new game and got to the Olegs and the items were in the chest.

I hope others also got the DLC and don't need to wait.

Me too.