Quality Score has very little to do with the actual content on the landing page, at least as long as its the QS Bot only. What matters are keyword/ad relevancy and CTR, so split those keywords up into relevant ad groups. Additionally, your domain or even the whole account can be sort of flagged, and you'll get shitty bids. Currently I have a campaign that uses a landing page with NO actual text on it, yet most of my keywords have a quality score of great with minimum bids of 0,04 or 0,05.