1 Across, Opportunity to use Latin in part of church (7)
5 Across, European arrested by US agent panicked (7)
9 Across, Considering taking up new position after retirement? (,7,4)
11 Across, Such riotous scenes in bachelor's wild parties? (4,4)
Many thanks brainiac and dannyk13. Had already realised my answer to
18 down was incorrect. Once I had seen it should be MISLAID rather than
MISLAYS, was able to complete the puzzle. Cheers both.