How often do folks do it?
There are two instances that we find ourselves falling back on.
1) Choosing Main Characters. Some characters are pretty vital, particularly to certain episodes. Serenity (2) without Book, for instance, that Rising Tensions means everyone gets a Flaw and there's no counter-balance. That's... kinda painful.
And Book's Talent ability to get rid of Flaws is incredibly useful in general. Some of the Flaws are crippling to the MC and the team.
Trying to beat the Triumph Bandits (Our Mrs. Reynolds) without Zoe is pretty difficult.
2) To Scan or Not to Scan. Sometimes not scanning is a better option. Not a great option (try beating those Side Jobs the turn they pop into the Combat Zone). But sometimes it's better than scanning. Serenity (2), for instance, scanning sets off the Patience Snipers. And the Patience Bandits protect each other. And you can't defeat Patience as long as there are Bandits in play. If the Snipers and Bandits come up in the 'Verse, you're boned.
With the game, you'd almost have to. They based the game on the specific episodes, and it seems like they balanced the game to be thematic, so metagaming to me seems like a must. For fans of the show, they can play with other characters and see how (if at all possible) it would've been for Book or Simon dealing with Patience instead of Mal/Zoe
1) In the episodes, some characters play a more vital role (for whatever reason) than others. Book is unbelievably invaluable at key moments in the show and often helps balance the tensions and emotions of the other characters (pretty important on a small ship with a fair bit of internal / external drama),
Kinda cheeky, but stealing the quote from the show about Zoe in Our Mrs. Reynolds, "Tactics" (keeping zoe in the back, who dives off the side of the wagon shooting_)
2) I feel like scanning is pretty much just hacking... the more you try to find someone / thing, the more likely you are to be discovered. You're right though, snipers + bandits is a recipe for disaster (but totally thematic, no?)