Just to point out, I won't be enforcing any rolls for character interaction, nor even roles. As long as you are playing within your ability scores, or story wise it feels right, then feel free to spot the actions and moods of the party members and post accordingly. I will leave it up to you players to regulate through OOC how that goes.
Of course, if for example OB wanted Westian to deliberately lie to the party about what he thinks their chances are, he is quite free to make a bluff roll to be opposed to others' sense motive checks. Similarly, if Haynuus wanted to quietly wipe a tear from his eye about the sadness of Ameena, he could make a sleight of hand check.

Again, that is up to the players.
I'll always be led by the players in how their players interract. You know, except for the times when I don't, which will always be for good fun reasons, have no fear
Similarly with character roles. You all have your classes, and you all have potential roles in the party. However, due to the ease of multiclassing and freedom of play, you can adapt your party how you all see fit. Haynuus can give up his club and be moved by Westian's religeon, becoming a pacifist. Falkor can realise there is as much fun in roguing and wizarding. There will always be options in how tasks can be beatenor overcome. As long as you then play well in the roles you choose, find your own roles!
Again, your DM will leave you alone in this regard, and not insist a party has a rogue nor wizard nor cleric nor fighter or else some encounter cannot be beaten. You DM does reserve the right to make other options less obvious, of course
