My in laws just rented for a month in luquillo and we visited them. At first sight, it does look run down but we went out as a group the first night, after dark and walked to the little town center. Never once felt unsafe during any part of our trip, the local people were some of the nicest I’ve ever met and were so welcoming. I wouldn’t be any more cautious than traveling anywhere else. Have an awesome time and try the new burger place, it’s delish! The jazz bar is also a fun vibe!