Actually, what scares me the most in the Tournament mode are phrases like:

What is this trading about? I couldn't find anything about trading in the manual.
And I don't know how to negotiate at all, so I'm even afraid to participate in the Tournament mode. :)

And another question about time.
Is there a total game time limit? I mean, if the time runs out, do you lose?
Sorry for these "childish" questions. :)

About Trading.
For example, you can agree on:
1) Drafting Castles;
2) Choosing Castles at will;
3) Negotiating for Castles generated by a randomizer and negotiating for the color.

For example, I might be okay with giving my opponent any Castle of their choice, and then choosing from the remaining ones for myself.

In general, you play according to whatever you agree on.

About time.
You can agree on a time limit, like in SoD, so that it stops during battles. You can set it in the settings so that the time does not stop during battles. Time is added each turn; if a certain amount of time was not used during a turn, the remaining time is added to the next turn. If the time runs out during the current turn, the turn is passed to the opponent after the battle is completed, or after entering (leaving) a Castle.

Overall, it works something like that.