QUOTE:  “Tell visitors clearly that the page they’re looking for can’t be found. Use language that is friendly and inviting. Make sure your 404 page uses the same look and feel (including navigation) as the rest of your site. Consider adding links to your most popular articles or posts, as well as a link to your site’s home page. Think about providing a way for users to report a broken link. No matter how beautiful and useful your custom 404 page, you probably don’t want it to appear in Google search results. In order to prevent 404 pages from being indexed by Google and other search engines, make sure that your webserver returns an actual 404 HTTP status code when a missing page is requested.” Google, 2018
Google will INDEX perhaps 1000s of characters in a title… but I don’t think anyone knows exactly how many characters or words Google will count AS a TITLE TAG when determining RELEVANCE OF A DOCUMENT for ranking purposes. It is a very hard thing to try to isolate accurately with all the testing and obfuscation Google uses to hide it’s ‘secret sauce’. I have had ranking success with longer titles – much longer titles. Google certainly reads ALL the words in your page title (unless you are spamming it silly, of course).
If you have original, quality content on a site, you also have a chance of generating inbound quality links (IBL). If your content is found on other websites, you will find it hard to get links, and it probably will not rank very well as Google favours diversity in its results. If you have original content of sufficient quality on your site, you can then let authority websites – those with online business authority – know about it, and they might link to you – this is called a quality backlink.
The last piece of the complicated SEO tool ecosystem is the enterprise tier. This roundup is geared toward SEO for small to midsize businesses (SMBs), for which these platforms are likely priced out of reach. But there's a handful of enterprise SEO software providers out there that essentially roll all of the self-service tools into one comprehensive platform. These platforms combine ongoing position monitoring, deep keyword research, and crawling with customizable reports andanalytics.
Ask for a technical and search audit for your site to learn what they think needs to be done, why, and what the expected outcome should be. You'll probably have to pay for this. You will probably have to give them read-only access to your site on Search Console. (At this stage, don't grant them write access.) Your prospective SEO should be able to give you realistic estimates of improvement, and an estimate of the work involved. If they guarantee you that their changes will give you first place in search results, find someone else.
Some pages are designed to manipulate users into clicking on certain types of links through visual design elements, such as page layout, organization, link placement, font color, images, etc. We will consider these kinds of pages to have deceptive page design. Use the Lowest rating if the page is deliberately designed to manipulate users to click on Ads, monetized links, or suspect download links with little or no effort to provide helpful MC.

Some page titles do better with a call to action – a call to action which reflects exactly a searcher’s intent (e.g. to learn something, or buy something, or hire something. THINK CAREFULLY before auto-generating keyword phrase footprints across a site using boiler-plating and article spinning techniques. Remember this is your hook in search engines, if Google chooses to use your page title in its search snippet, and there is a lot of competing pages out there in 2019.

Thank you for the great checklist. It is really useful and gave us a couple of new hints on optimization process. We’ve been using WebSite Auditor and found it exremely helpful in site’s structure and content analysis, bringing all the statistical information on the validation errors, social mentions, duplicate stuff, etc. under one roof. Still there is so many different SEO information you sometimes cannot understand what to start with. Fortunately you answered this question. Thank you again!