I have a few questions about the Pros and Cons of whether it is better to allow WordPress to host your site or whether you should download and manage your own "decentralized" WordPress instance and what impact that has on traffic, user comments, and participation. This really can be abstracted to any blog platform but I'm asking here since I'm wanting to stick with WordPress.
There is no question that managing your own decentralized WordPress instance will give you superior flexibility and control over your blog, especially as it seems plugins are not available for WordPress hosted sites (I have noted the documentation here: http://en.support.wordpress.com/com-vs-org/). However I have two chief concerns of "taking my blog and going home" that at first glance would seem inferior to the online WordPress blog hosting: visibility and user comments.
I'll deal with visibility in a moment but comments are my primary concern. If I host my own WordPress instance does that not mean that I will have to maintain my own user login database or have to settle for (potentially) anonymous user comments or "typed in" names, versus the convenient unified userspace on wordpress.com that allows any registered wordpress.com user to use their profile to comment on a hosted WordPress blog? Or maybe even if that is the default are there plugins to allow authentication against wordpress.com to allow people to comment on my personal WordPress instance?
Secondly, as concerns visibility, how do you "publicize" your blog if it is not hosted on a centralized (and recognized) blogging name space like wordpress.com or blogger.com? Sure Google will index your site but is it more likely that you will initially get less traffic to your individual WordPress instance than if you had from the start hosted it on wordpress.com.
I posted a completely brand new blog just a few days ago on wordpress.com and within 4 hours I got 5 likes on the opening article. I can't imagine such visibility would be available from the start if I had hosted my own instance of WordPress.
Can anyone with some experience address these concerns and perhaps offer any advice, corrrections, or clarifications?