Paul is saying the man is acting like the devil. Alternate translation: "You are like the devil" or "You act like the devil" (See: [[rc://en/ta/man/translate/figs-metonymy]])
Paul uses this question to rebuke Elymas for opposing God. Alternate translation: "You are always saying that the truth about the Lord God is false!" (See: [[rc://en/ta/man/translate/figs-rquestion]])
Here "straight paths" refer to the ways that are true. Alternate translation: "the true ways of the Lord" (See: [[rc://en/ta/man/translate/figs-idiom]])