Navigator: As bad as it looks.
It must look pretty good to you! Navigator's not bad.
It's not next to useless like Thief or Scout, but realistically speaking it is pretty bad. It has some nice synergy with Royal Seal, Native Village, Wishing Well, Mystic and probably some others, but that's pretty much it.
Kirian: Not true. KC-Warehouse at the start of your turn leaves you with three cards in hand, because KC is -1 card, Warehouse is -1 card and every Warehouse effect is +3 -3 which is 0.