WordPress重写:动态URL解析

On a WordPress based site, I'm trying to do something like Twitter or Facebook's username URL suffix. Member URLs would be something like:

domain.com/username

However, we also have custom pages that are hosted on the same domain root. Example of the URLs are:

domain.com/contact
domain.com/support
domain.com/register
domain.com/login

I have considered adding custom rules for each user by binding WordPress' WP_Rewrite to the user_register action but I learned that this would be stored in the options table under the rewrite_rules column, the value of which is stored in longtext. I'm concerned with the scalability of this approach and possible drawbacks against future DB performance.

Basically, we first have to check if the request made is of a valid existing username, and if not, check if it's a valid WordPress post or page, and if not, redirect to the 404 page.

Note that we don't want our own pages to have a prefix ( e.g. domain.com/p/contact ).

How do I go about solving this one?

Thank you very much.