Page Rank has lost its importance, now the factors which play the most important part in Indexing your pages in Search Engines are:- 1. Keyword Targeted anchor text from external links 2. Quality and Quantity of external links 3. Keyword which is used in the external links 4. Diversity of links from several unique domains 5. Trustworthiness of your domain Of the given factors first three are external and they do not depend on your on your optimization.
That is a good list of 5 factors, it is because Indexing helps the researcher to find a better and easy way of looking sites that is very fitted to their niche. Indexing is a passive investment strategy. An investor can achieve the same risk and return of an index by investing in an index fund.
"updating your blog regularly" is another important factor, I guess. I dont know about other search engines but Google consider your update frequency for showing search results.
name of your domain is important too..it could help you rank easier, but sometimes domain name that have keywords looks spammy the other important thing is <title> and meta description
i may surely agree to all your points being mentioned by i doubt to fifth one as worthiness of domain is measured by google in terms of its AGE!!