Usually one

Just one card causes a failure. Exception: for one mission, the tableau indicates that two fail cards are needed.

Yes!

Evil players have a free choice whether to support or sabotage -- it depends what they think will best further their ends.

No

No, good players must choose to support a mission. (Why would you want to sabotage it anyway?)

The board

It's just a fancy name for the game board.

It depends

The tableau shows how many team tokens to give out for each mission.

No

No, everyone knows who has the token.

No

No, it's a token. You get a character card too.

Leader's right

The player to the right of the leader gets the token at the start of the game.

No

You have to do the missions in order. The leader can't choose a mission unless you're using the targeting variant, and even then, there are some rules about what's what.

Yes

In the regular game, yes. If you don't want this, you can use the blind spies variant.

Randomly choose

Just pick someone at random.

After the third successful mission (Resistance wins), or the third failed mission (Spies win), or if there are five consecutive failed votes in a single round (Spies win).

No

No, this would break the game. You can tell people what card you hold (or lie about it), but never actually show it.

Yes

Yes

Yes

Yes!

It is rejected

A majority is needed to approve a team. So if the vote is a tie, it is rejected.

No

Not at the same time, no.

You are allowed to lie or tell the truth about your affiliation or other players'. You are allowed to admit or misrepresent your beliefs and any information you have. However, you are not allowed actually to REVEAL your affiliation or anyone else's, e.g. by showing others your character card or describing its appearance.

Use variants

You can use the inquisitor or blind spies variants to make the game more difficult for the spies if you find that they win too often.