TrilceAC Hi, thanks for your questions!
For ties in culture points, adjacent score values are averaged.
This means that if you tie with somebody else in a specific game, your gain of tournament score is averaged over the tie's span. For example, if two players tie for the 1st place in a 4P game, each scores (6+3)/2 = 4.5 points.
And for your second question, yes, for ties in tournament scores we will strictly adhere to the stated tie-breaking rules, although they are not reflected on this website. You will rank 3rd in Group 17. (I don't even know how the game website breaks ties by default! 🙂) We will probably make an annoucement about the tie-breaking results after each stage finishes.