What do we do about this concerning inspection report?

We put an offer on a house below asking. Buyer said they’d accept it without an inspection: we countered a little higher insisting on inspection and they accepted.

Nothing failed inspection but there were quite a few defects—sinks leak, missing insulation, etc. The major concern is a sewer pipe cracked in two places, so we got a plumber to give a quote (no report yet but it’s a big project). After taking down panels, plumber discovered 2 dead rats in the wall by the pipe. There’s also a small room/area nearby filled with basically trash, and this is on top of stuff left in the yard, shed, etc

The house was built in 1940 so we expected to be fixing things, and rodents are going to pop up in any city house, so each individual thing isn’t an issue, but we’re starting to get worried about what the condition of the place really is. Did they not want an inspection because they knew about this stuff and hoped we wouldn’t find out? Or, maybe worse, did they not know or care they had rats in the walls? What else is going to pop up?

We don’t need perfection but we want to be moving in to somewhere clean that we can make our own! What is the right move here?

We’re waiting for a sewer scope today and the plumber estimate and thinking we’ll ask for a significant seller assist and removal of all belongings plus animal removal. We love the neighborhood so much and want to make it work but are definitely secong guessing.