I mean, if you want to avoid the specifics then you get the general flow being
Depending on whether it’s GA or big airline you get all the steps like check-in and stuff as your “additional steps” so clearly your intent was to go into the specifics ;p
So on your original list I believe 1st class passengers are less likely to shop, more likely to go to a first class lounge and wait, then get priority boarding, whereas 2nd class are more likely to go for an explore round the duty free and sit in coffee shops, or go for a smoke in the smoking area.
There would be a degree of randomness in it where first class passengers might go shopping and things like that as you say with adding additional steps.
However I don’t think this topic needs particular discussion as it’s already implemented and quite obvious as to how it works. The frequencies of each particular aspect might need refining and more options for additional tasks might be added, each step made into sub steps and such like depending on your facilities, but i’m sure the developers are on it given it’s the main focus of the game and the part we will be constantly interacting with, for a good game it needs to be right.