Thanks for the questions on the card!
1) The discard must be Equal to the influence of the dude, this is the requirement to playing the card. So if you have a 3 INF dude and 2 cards in hand, you couldn't play the card.
2) In the case that a dude's influence is greater than 3, The 'maximum of 3' limits both the discard AND drawing of cards. So if you had a 4 influence dude, and wanted to play the Winning Agenda, targeting that dude: You would have to discard 3 cards; and then you draw 3 cards.