Moving WordPress blog from subdomain on same server
===

I have my website and WordPress installed on a Linode server running Ubuntu.
The directories are:
~/public_html - Website
~/public_blog - WordPress installation

My DNS and site config is set up so that:
hashbang0.com - Points to website in ~/public_html
blog.hashbang0.com - Points to WordPress install in ~/public_blog

Site config as follows:

    <VirtualHost 123.456.789.000:80>
         ServerAdmin user@gmail.com
         ServerName hashbang0.com
         ServerAlias www.hashbang0.com
         DocumentRoot /home/user/public_html/
         ErrorLog /home/user/log/error.log
         CustomLog /home/user/log/access.log combined
    </VirtualHost>
    
    <VirtualHost 123.456.789.000:80>
         ServerAdmin user@gmail.com
         ServerName blog.user.com
         ServerAlias blog.user.com
         DocumentRoot /home/user/public_blog/
         ErrorLog /home/hashbang0/log/blog_error.log
         CustomLog /home/hashbang0/log/blog_access.log combined
    </VirtualHost>

Now, I have had enough of tinkering with PHP, HTML, etc. I want to move my WordPress installation so that visitors to hashbang0.com see the WordPress site. At the same time, anyone with links to the old blog.hashbang0.com (most notably RSS feeds and a few links spattered about which gain a fair amount of traffic, etc.) shouldn't be cut off (possibly be redirected to the appropriate thing on hashbang0.com).

I guess I could possibly change the site config to:

    <VirtualHost 123.456.789.000:80>
         ServerAdmin user@gmail.com
         ServerName hashbang0.com
         ServerAlias www.hashbang0.com
         DocumentRoot /home/user/public_blog/
         ErrorLog /home/user/log/error.log
         CustomLog /home/user/log/access.log combined 
    </VirtualHost>

And I guess I'd need to update the URL in Settings > General?

I don't want to start moving stuff and find I've shot myself in the foot.  The WordPress howtos are great, but riddled with if this and if that...

Any help would be very much appreciated.

Ben