Sorry to hear of the disagreement. I think we all have one or more wooda-shoulda-coulda moment we can point to in this hobby. I purchased an expensive machine that was in "minty new - out of the box" condition that had some flashers not working properly. This guy lied to my face and told me it worked that way since it was new. Ended up being shorted wire caused by an incorrectly installed mod blowing a transistor on the driver board. My fault for not taking the time to inspect more closely at pickup.
Hate to say it but if condition of the machine (inserts,etc) was that important, you should have taken more time to inspect the machine. That would have still left you with the operational issues, but at least it would have reduced one or more pain-points from your list.