Splendor

No. You can take two of the same color only if at least four tokens of that color are available when you take them (p. 3).

You must return tokens until you have 10 or fewer, and you may return any tokens you just took (p. 3).

Reserving a card is the only way to get a gold token; if none are available, you may still reserve but get no gold. You can have no more than three reserved cards, and can only get rid of one by buying it (p. 3).

Yes. Each bonus counts as one token of its color toward a purchase, reducing how many tokens you need to spend; bonuses can cover the full cost (p. 4).

No, a qualifying noble visit is automatic and is not an action. If you qualify for multiple nobles at the end of your turn, choose one (pp. 3–4).

Not immediately: finish the current round so everyone has had the same number of turns. The player with the most points wins; if tied, the player who bought fewer development cards wins (p. 4).