This tool works, it’s just a little antiquated in speed. But it is also one of about 4 auditors available to you on our site. If you decide you don’t feel like waiting check out our best free tool Ultimate SEO Tool or visit our tools area.
There isn't a right or wrong answer necessarily because Google changes often but the following provides guidance thats generally accepted.
Two most important factors for a page or keyword to rank aren't even On Page SEO. Backlinks and User Behavior! Don't believe me? Search "Google Bomb" and read about the time Google ranked someone as a Miserable Failure with no mention of the word on the site.