The phrase "had qualms" refers to a feeling of uncertainty or hesitation about something. Antonyms for this phrase could include "confident," "sure," or "assured." These terms suggest a sense of conviction or certainty about a decision or action. Other possible antonyms for "had qualms" might include "unwavering," "unhesitant," or "resolute." These words imply a strong sense of determination and lack of doubt or hesitation. These antonyms could be useful to use when discussing someone who is certain, confident, and unwavering in their beliefs or actions, and can help to convey a sense of confidence or conviction.