I agree, most of these issues are just growing pains as a new user learns the site. My go-to copy & paste messages are as follows:
For observations with multiple species uploaded as a single observation:
Each species should be its own separate observation for ID to continue. There are some tips for splitting the observation up here: https://forum.inaturalist.org/t/how-to-fix-your-observation-with-photos-of-multiple-species/15096
For multiple observations of something that appears to be the same individual (but not duplicate photos):
Is this the same individual as you subsequent observation: insert link here? If so, please combine all photos into a single observation. There are tips for combing your observations here: https://forum.inaturalist.org/t/how-to-turn-multiple-observations-into-a-single-observation/9838. If this is a different individual, then separate observations as you have them is fine.
For duplicate observations where the exact same photos are used:
Hi, looks like you accidently uploaded a duplicate: insert link here. Would you mind deleting the second observation? Thanks!