A breadcrumb is a row of internal links at the top or bottom of the page that allows visitors to quickly navigate back to a previous section or the root page. Many breadcrumbs have the most general page (usually the root page) as the first, leftmost link and list the more specific sections out to the right. We recommend using breadcrumb structured data markup28 when showing breadcrumbs.
When Googlebot crawls a page, it should see the page the same way an average user does15. For optimal rendering and indexing, always allow Googlebot access to the JavaScript, CSS, and image files used by your website. If your site's robots.txt file disallows crawling of these assets, it directly harms how well our algorithms render and index your content. This can result in suboptimal rankings.
Think of it this way: The more specific your content, the more specific the needs of your audience are -- and the more likely you'll convert this traffic into leads. This is how Google finds value in the websites it crawls; the pages that dig into the interworkings of a general topic are seen as the best answer to a person's query, and will rank higher.
What is Search Engine Optimization (also known as SEO)? A broad definition is that search engine optimization is the art and science of making web pages attractive to search engines. More narrowly, SEO seeks to tweak particular factors known to affect search engine standing to make certain pages more attractive to search engines than other web pages that are vying for the same keywords or keyword phrases.
Relevancy is the first qualifier of a quality link opportunity. The next qualifying factor is the authority of the opportunity. Since Google doesn’t update PageRank (PR) anymore, you must rely on third party metrics. I recommend you use Domain Authority (DA) from Open Site Explorer, Domain Rate (DR) from Ahrefs, or Trust Flow from Majestic to determine the quality of your link opportunities. You should use all three tools if you can.

That second link will still help you because it will pass extra PR to that page. But in terms of anchor text, most of the experiments I’ve seen show that the second link’s anchor text probably doesn’t help. That being said, Google is more sophisticated than when a lot of these came out so they may count both anchors. But to stay on the safe side I recommend adding keywords to navigation links if possible.
#16 is interesting because no one really knows about it. Myself and a former colleagu did a test on it about 4 years ago and published our results which conculded what you are saying. Since then I’ve been careful to follow this rule. The only issue is that often times using the exact kw does not “work” for navigation anchor texts. But with a little CSS trickery one can get the code for the nav bar to be lower in the code, prioritizing contextual links. I’ve also seen sites add links to 3-5 specific and important internal pages with keyword rich anchor texts, at the very top of the page in order to get those important internal links to be indexed first.

Current search engine optimization focuses on techniques such as making sure that each web page has appropriate title tags and that the content is not "thin" or low-quality. High-quality content is original, authoritative, factual, grammatically correct, and engaging to users. Poorly edited articles with spelling and grammatical errors will be demoted by search engines. For more information on thin content see More Guidance on Building High-quality Sites.
Every time I write new content I post it to twitter. If you use the right keywords and make your tweet interesting enough you can get a lot of clickthroughs just from people searching. For example if I write an article about SEO and Google I can tag the end of the tweet with #SEO #Google and anyone that searches for those keywords on Twitter can see my tweet about the post that I wrote. Be sure to write creative headlines for your posts so people feel the urge to click on them.
Instead, in this instance, we started at wireframe stage, plopping in keywords and meta tags. Of course, the site really needed those things, and although it launched technically “optimized”, it wasn’t enough to provide a better product than our top competitor(s). A product that people want to visit, revisit, email to friends, share on social networks, and link to more than our competitors. It wasn’t even enough to move up in the rankings.
The leading search engines, such as Google, Bing and Yahoo!, use crawlers to find pages for their algorithmic search results. Pages that are linked from other search engine indexed pages do not need to be submitted because they are found automatically. The Yahoo! Directory and DMOZ, two major directories which closed in 2014 and 2017 respectively, both required manual submission and human editorial review.[40] Google offers Google Search Console, for which an XML Sitemap feed can be created and submitted for free to ensure that all pages are found, especially pages that are not discoverable by automatically following links[41] in addition to their URL submission console.[42] Yahoo! formerly operated a paid submission service that guaranteed crawling for a cost per click;[43] however, this practice was discontinued in 2009.