Yes, multiple instances of exalted stack
Wizards of the Coast has recently changed its approach to updating the banlist and is creating a more flexible approach to updating it, stating that "Future banned and restricted announcements will occur two to five weeks after each set's release." This does depend on which formatting you are playing though, so it's still worth getting familiar with the banlist update cycles and the latest releases
The more packs you crack, the more accurate the EV will become because you smooth out these outliers
As you will likely be fielding plenty of strong characters, you can really benefit from Narrow Advantage against decks that dont bother with playing equally strong characters
The last ability of Queen Marchesa (long may she reign) checks to see if an opponent is the monarch as your upkeep begins
Even if a set has a relatively small SAR pool, the box still has to hit the SAR layer and then hit the correct card inside that layer