wiring for wall sconces
Let's be practical  about this one. The area of concern on your part is the wire that is resting on the ceiling drywall. In a perfect world, if you had had access to the space then the wire should have been secured to avoid any nail damage etc. It sounds like you did the rest of the installation well where you had access. If the cable in the closed ceiling is not visible without removing drywall, then it is highly unlikely a home inspector will even see it. I'm not advocating hiding problems from a home inspector,(I am a home inspector) but keep in mind that a home inspector is not a government building inspector and typically is not allowed destructive/invasive inspection techniques. If the cable is fully enclosed, it will not be seen.  Let us assume that the inspector sees and makes an issue of the unsecured cable. Normally, the finding would be addressed before a closing. It would be rare that a minor problem like this would sink a sale unless the buyer was looking for some way out of the deal and refused to allow you to remedy the problem. Personally, I would never write up such a minor discrepancy unless I felt it posed a safety problem. Most electricians I know would probably do the same by fishing the wire in an open bay and securing it in the first exposed area available.