1: The board is under with Sesto. Technically, he still has it; he just hasn't managed to get on it. I assume it's harder to use when you're not the one commanding it. RAW you can only fly it if you say the command word. Lorenn is still in command of it, ATM.
2: Easier said than done.
3: Overrated. Seriously, though, it's a good tactic in the game, but I find using it to excess sometimes makes things narratively strange. It's because of the way the game works that it's such a good tactic, but IRL it would have limited uses (more in a modern conflict than in a traditional one). The point it falls apart for me (immersion-wise) is when people turn away from an opponent they are actively fighting to focus-fire on someone else. You'd get yourself killed if you did that and pick-your-partner combat works better in those cases.
Anyway, that's not happening here yet, so feel free to focus-fire more than you are! Ranged (and Spell) attackers have the luxury of scanning the field for where their efforts would work best, in particular when they are off on their own and not being targeted. That's where it best doesn't effect my sense of immersion.
