皇輿爭霸之暗潮洶湧

Treasure cards are normally played during your Buy phase: you may play some or all Treasure cards from your hand then and add any coins from Action cards to pay for purchases; Treasures remain in play until Clean-up. (page 4)

For Pawn you must pick two different options (you cannot pick the same option twice) and then perform both in either order; for Nobles you choose one of the two options and cannot mix them — in general, once you make a choice you must complete as much of it as you can and you cannot change it later. (pages 8, 6)

If you must draw/reveal more cards than are left in your deck, draw/reveal as many as you can, then shuffle your face-up discard pile to form a new deck and continue drawing/revealing the remainder; you do not shuffle until you need to. (pages 3, 6)

Yes — multi-type cards are all of their listed types for every purpose (e.g., Great Hall and Nobles are both Action and Victory; Harem is Treasure and Victory) and interact accordingly. (pages 6, 8)

You may reveal multiple Reaction cards to a single event, but each Reaction must be completely resolved before revealing the next one; a Reaction revealed and resolved can allow you to then reveal another Reaction. (pages 6, 9)

If you need to shuffle to continue revealing, do not shuffle the already revealed cards back in; shuffle your discard to form a new deck and continue revealing, and if you go through all your cards without finding a qualifying card you discard the revealed cards. (page 8)