Keep in mind this is one mans decision, not the dealership it self. Just because the sales person is a loser and the sales manager is a dickhead it shouldn’t prevent you from getting a good deal. If they honour the advertised price and you really like the car and you can’t find that car for a better deal anywhere else then why not buy it.
The only thing I would demand for the trouble they put you through is for them to fix anything that doesn’t work, fix any scuffs or damages on the body and do the next big service at no charge when the time comes.
If the car is perfect then demand new tires, rotors and pads. Most dealership will not change those things if they pass safety. The tires, rotors and pads might pass safety now but barely, meaning in 2 month’s you might have to replace those things, so why not get new ones put on, that way you know you will not have any major expenses any time soon.
That’s my 2 cents.