Disabling htaccess is a good idea to speed up apache. If AllowOverride is set to All apache will watch all folders recursiv for htaccess files. Than coasts performance. First IO operation on the harddisc and than using that rules from htaccess coast cpu usage and time.
The hardest thing about putting the rules from .htaccess into the httpd.conf is how to rewrite the rules that they work in the httpd.conf? I found a nice page with offers a php script to generates the code from your htaccess files for the httpdc.conf
http://blog.preinheimer.com/index.php?/archives/340-.htaccess-to-httpd.conf.html
Have fun and a better performance