when parents register their dogs why is it that they are able to put them all on the same line rather than rover letting them know each dog has to be registered individually?

Until the owners go in and fix it, then you will have to manually adjust. My suggestion is to offer to help the owner fill in complete info on all their pets since so much depends on accurate info, not just your bill. Tell them that it is important for insurance reasons. Each animal needs to be separately identified. Some people take shortcuts, don't want to spend the time, or can't figure out how to "add" another pet. I know, it seems simple, but that may be what you have to do to get it fixed.

I would never adjust the price. You expose yourself to a bad review if anything goes wrong, and Rover's protections don't apply because of it. There are some stories floating around about Rover not standing behind sitters who may have (inadvertantly) contributed to a problem like that.

Before accepting the request, I would require the dog owner to create profiles for each dog, and book each dog. If that was a deal-breaker for them (if they went with someone else) I would flag the conversation so Rover is aware of a problem brewing.

I've reported 2-3 conversations that concerned me like that. Rover seems very happy to have that "heads up" awareness.

(There are other threads where it's been discussed that Rover could put more emphasis on the owner's profile. It often seems like the weak link in the process, often many empty profiles, no info, etc.).