Letter seems amazing to me, comparable to Blightning in MtG (though maybe that'd be more like loses 2 honor and discards 2 cards). Retreat really feels like it should cost 0 for taking a card in your hand. Also seems like it 'should' be a lion card, but at least it has lion on the art.
I don't know who you guys assassinated, but Lion gets no respect from FFG.
Iwasaki pupil's probably the most interesting of this bunch. This is the card that will give crane honor decks a boost towards viability. Cutting down the card discrepancy between low bids and high bids will help them not fall so far behind. It feels like it should be a conflict card, but I guess they didn't want to bring up the fact that you'd always miss the draw phase the turn you play it like that.