My experience backs up David's opinion. Google doesn't care if your NASA if you're trying to sell cheese & crackers. Since that's not what users are searching for it's not advantageous for Google to show people NASA ads. No one really wants astronaut cheese anyway (wait... is that string cheese?
maybe they do)
Auction bids & quality score are based heavily on estimated click through rate, landing page experience, ad relevance, and ad formats. LP Experience can be measured in several ways and Google has always been really keen to keep that information under lock & key. There are theories that they look at time on site, bounce back rate, click through rate, conversion rates, etc. But there's no real answer - except that I am very confident that the specific page's authority is not a heavily weighted factor.
I know you came here for a customized response that's more in depth than static information on the web, but I'm going to direct you to this video anyway because it's seriously informative
http://searchengineland.com/google-new-adwords-ad-rank-video-195049
It's legit. I see this happen every day.
There are many theories behind what goes into landing page relevance, but the authority of that page is insignificant. Thousands of companies use PPC specific landing pages that are excluded from robots.txt and have high QS.
I understand that 10% can make a huge difference when you're on the cusp of getting to an 8, 9, or 10, but overall there is more you will be able to do in the account that will impact QS than what you can do with your landing page. (that's not to say that CRO isn't beneficial, but that's CRO, not QSO - quality score optimisation)
I'd rather guide you in the direction of your negative keywords and keyword grouping techniques. the more specific your keywords are to your copy to your landing page the higher quality score you will receive. Note: I said specific. "Cheese" as a head term is not a specific query... "11 in bamboo cheese board" is a very specific query.
Got a little side tracked there. Hope this information is still useful to you! 