Here's one I'm still working on:
Honor bidding. Is it generally the case that a given deck in a given matchup wants to always bid 5 or always bid 1, or should you vary your bid (excluding cases where you obviously do, such as I can swim or Good Omen).
If you're running Crab dishonor, for example, is it best to open with a "high" bid of 3+ in order to initially populate your hand with more options and bombs to credibly threaten plays like Way of the Crab, and then switch to 1 for the rest of the game to choke honor, or is it better to do bids of 1 right off the bat, or should you be adjusting more adaptably based on hand size or board state?
Generally we know when you should lower your bid - if honor matters to you or your opponent and you don't think you need the cards. When should you RAISE your bid, if ever?
Suppose you're in a tight spot and the game is going against you, and honor is fairly neutral between players. Bid 5 to hope for a big swing-out, even at the cost of honor? What would you use to evaluate that decision in a game state?
I think another point that would be good for this game is a basic guide on the "big bombs" from each faction and how to play around them. Understanding how to play to avoid getting your big guys hit by I can swim, Way of the Crab, understanding how to play around Forged Edict and Voice of honor (being careful about using cards with high costs while those cards are usable, for example - much more painful to get an assassinate or way of the crab cancelled than a rout, for example).
I'm pretty paranoid about things like this, but I know a lot of new players are likely to walk into some serious misplays (especially vs. Scorpion) when they don't know about this tech, know how to watch for it, or know the best ways to play around it.