Do I have to have a host such as Bluepost or iPage to blog effectively? Is there an advantage to a host that I don’t get through WordPress? Do I have to subscribe to the business version of WordPress to use the reftagger plugin?
1) Having your site hosted through WordPress doesn’t affect your ability to blog effectively. If you would like to have a more custom url, you can upgrade to a paid account to remove the wordpress.com: https://en.support.wordpress.com/plan-features/