She was speechless at his harsh criticism.
The article sharply satirizes the government's policy.
辛辣 is a na-adjective meaning scathing or cutting, usually describing criticism or remarks, whereas 口が悪い describes the speaker's general manner of talking.
辛辣 is an adjective meaning scathing or harsh (of words, criticism, or writing), while 毒舌 is a noun naming the trait or speech act of being sharp-tongued.
Standard kanji spelling.
Mixed kanji-kana spelling; less common but still encountered.
From Chinese 辛辣 (xīnlà), literally 'acrid' or 'pungent', combining 辛 (spicy, bitter) and 辣 (hot, pungent). The Japanese reading しんらつ is the on'yomi.