The final walk thru is not an opportunity for the buyer to "renegotiate" your deal. It is simply to make sure whatever was supposed to be included in the sale was left (appliances, light fixtures etc). It is also to make sure everything is in working order and in the same condition as when they put the offer in on the house. The carpet is the carpet, and it was the same when they looked at it. It doesnt sound like you are going to have a problem. Occasionally, some buyers feel like the walk thru is another opportunity for a 2nd home inspection. Unless something is broken or drastically changed, you should say "no" to any credits at closing.

Saltidawg, I agree. If a pipe were to break, or a valve fail, or vandals came in and tagged the place, or sellers came back and removed appliances/lights/etc, you would not know when you closed, and you own the house after you sign. Do the final walk through on the way to closing. If you had items that seller agreed to repair, you should be getting those checked as soon as they are done, to allow time to get them corrected, if they were not done. But the walk thru should be as close to closing as possible...within a couple of hours, but the same day for sure.

A Certificate of Occupancy is granted by the city when the builder has met all of their requirements. You will not be involved in that process. Definitely ask for a key if you want it but don't be surprised if the builder wants to be sure nothing gets scratched or a window or door doesn't get left open at this late date. Don't let anyone rush you; say you need more time if you feel rushed. They signed a contract saying they would deliver a completely finished and working house so make them meet that obligation. Turn everything on and look in every corner, check every switch, door & knob and sight along every wall with a strong LED flashlight. Bring someone along to take notes. I don't know how to schedule a private home inspector; you need to ask the builder about that. I'm an architect and a builder would expect me to have inspected the house every few weeks especially before things were covered up. At this stage all you can discover are poor finishes or things that don't work and your contractor should have already found them. Remember, signing off on the house does not in any way relieve the contractor of his responsibility for building to the requirements of the contract documents. Don't sign anything that says otherwise. A walk-through should only be a courtesy.

Tell him you are not happy and you want it repaired or replaced to your satisfaction.