Be aware that years ago, passengers decided to evacuate an airplane because of excess fuel from an APU start, which was under the right wing.
Will your Flight Attendants TELL YOU anytime they see anything which is abnormal, even fairly minor, unusual sounds and fluid leaks? If they find the Captain easy to chat with, and the Captain seems open to any useful information, they might not think twice about it.
With less obvious, minor abnormalities, after they find out that the c0ckp1t crew appear cold, arrogant or insulting etc, they might keep quiet. This happened between a (Western?) DC-10 FO and Captain years ago landing in Mexico City, and it led to a tragedy.