I'm sure I'm not the first to ask this - but as I read the plot cards some of them seem obvious in who they apply to
eg Valar - applies to all in play characters
Power of arms - refers to characters 'you' control - given that a specific player plays that card - does the plot only apply to that player - it is after all a plot they have chosen to play to benefit them
Calm over westeros I suggest applies to all as it just says a player
Again holding the trident - this seems a bit of an own goal if it's played and an opponent has fewer characters - it also refers to 'you' - ie the drawer of the card
Mutual enemies - refers to mutiple opponents - in a 2 player game does this become nullified as it uses the words IF YOU HAVE MORE THAN ONE OPPONENT
herdiing the masses - to me is clear applies to all as it doesn't specify you or opponent it just states non unique characters
Mad kings legacy - is hard - and I'd say it applies to all players but isn't specific to cards they control so they could remove a negative condition attachment.
Sorry for the mass of examples - we've just really started playing properly and are trying to clarify the funnies!
Thankyou