The use of slug-less author page permalinks are not possible without causing 404 errors on static pages. Lets see why:
Normal rewrite rules for author pages:
[author/([^/]+)/feed/(feed|rdf|rss|rss2|atom)/?$] => index.php?author_name=$matches[1]&feed=$matches[2]
[author/([^/]+)/(feed|rdf|rss|rss2|atom)/?$] => index.php?author_name=$matches[1]&feed=$matches[2]
[author/([^/]+)/page/?([0-9]{1,})/?$] => index.php?author_name=$matches[1]&paged=$matches[2]
[author/([^/]+)/?$] => index.php?author_name=$matches[1]
Rewrite rules without the “/author” slug:
[([^/]+)/feed/(feed|rdf|rss|rss2|atom)/?$] => index.php?author_name=$matches[1]&feed=$matches[2]
[([^/]+)/(feed|rdf|rss|rss2|atom)/?$] => index.php?author_name=$matches[1]&feed=$matches[2]
[([^/]+)/page/?([0-9]{1,})/?$] => index.php?author_name=$matches[1]&paged=$matches[2]
[([^/]+)/?$] => index.php?author_name=$matches[1]
The 4th line above conflicts with the rewrite rule for pages which appears last in the list of rewrite rules:
[(.?.+?)(/[0-9]+)?/?$] => index.php?pagename=$matches[1]&page=$matches[2]
This means that any requests for pages are handled as if it was a request for an author page. A static /about page would return 404 because the system could not find an author slug of “about”.
Rewrite rules used on a wordpress blog with a standard /yerar/month/postname/ permalink structure:
[category/(.+?)/feed/(feed|rdf|rss|rss2|atom)/?$] => index.php?category_name=$matches[1]&feed=$matches[2]
[category/(.+?)/(feed|rdf|rss|rss2|atom)/?$] => index.php?category_name=$matches[1]&feed=$matches[2]
[category/(.+?)/page/?([0-9]{1,})/?$] => index.php?category_name=$matches[1]&paged=$matches[2]
[category/(.+?)/?$] => index.php?category_name=$matches[1]
[tag/([^/]+)/feed/(feed|rdf|rss|rss2|atom)/?$] => index.php?tag=$matches[1]&feed=$matches[2]
[tag/([^/]+)/(feed|rdf|rss|rss2|atom)/?$] => index.php?tag=$matches[1]&feed=$matches[2]
[tag/([^/]+)/page/?([0-9]{1,})/?$] => index.php?tag=$matches[1]&paged=$matches[2]
[tag/([^/]+)/?$] => index.php?tag=$matches[1]
[type/([^/]+)/feed/(feed|rdf|rss|rss2|atom)/?$] => index.php?post_format=$matches[1]&feed=$matches[2]
[type/([^/]+)/(feed|rdf|rss|rss2|atom)/?$] => index.php?post_format=$matches[1]&feed=$matches[2]
[type/([^/]+)/page/?([0-9]{1,})/?$] => index.php?post_format=$matches[1]&paged=$matches[2]
[type/([^/]+)/?$] => index.php?post_format=$matches[1]
[robots\.txt$] => index.php?robots=1
[.*wp-(atom|rdf|rss|rss2|feed|commentsrss2)\.php$] => index.php?feed=old
[.*wp-app\.php(/.*)?$] => index.php?error=403
[.*wp-signup.php$] => index.php?signup=true
[.*wp-activate.php$] => index.php?activate=true
[.*wp-register.php$] => index.php?register=true
[feed/(feed|rdf|rss|rss2|atom)/?$] => index.php?&feed=$matches[1]
[(feed|rdf|rss|rss2|atom)/?$] => index.php?&feed=$matches[1]
[page/?([0-9]{1,})/?$] => index.php?&paged=$matches[1]
[comments/feed/(feed|rdf|rss|rss2|atom)/?$] => index.php?&feed=$matches[1]&withcomments=1
[comments/(feed|rdf|rss|rss2|atom)/?$] => index.php?&feed=$matches[1]&withcomments=1
[search/(.+)/feed/(feed|rdf|rss|rss2|atom)/?$] => index.php?s=$matches[1]&feed=$matches[2]
[search/(.+)/(feed|rdf|rss|rss2|atom)/?$] => index.php?s=$matches[1]&feed=$matches[2]
[search/(.+)/page/?([0-9]{1,})/?$] => index.php?s=$matches[1]&paged=$matches[2]
[search/(.+)/?$] => index.php?s=$matches[1]
[author/([^/]+)/feed/(feed|rdf|rss|rss2|atom)/?$] => index.php?author_name=$matches[1]&feed=$matches[2]
[author/([^/]+)/(feed|rdf|rss|rss2|atom)/?$] => index.php?author_name=$matches[1]&feed=$matches[2]
[author/([^/]+)/page/?([0-9]{1,})/?$] => index.php?author_name=$matches[1]&paged=$matches[2]
[author/([^/]+)/?$] => index.php?author_name=$matches[1]
[([0-9]{4})/([0-9]{1,2})/([0-9]{1,2})/feed/(feed|rdf|rss|rss2|atom)/?$] => index.php?year=$matches[1]&monthnum=$matches[2]&day=$matches[3]&feed=$matches[4]
[([0-9]{4})/([0-9]{1,2})/([0-9]{1,2})/(feed|rdf|rss|rss2|atom)/?$] => index.php?year=$matches[1]&monthnum=$matches[2]&day=$matches[3]&feed=$matches[4]
[([0-9]{4})/([0-9]{1,2})/([0-9]{1,2})/page/?([0-9]{1,})/?$] => index.php?year=$matches[1]&monthnum=$matches[2]&day=$matches[3]&paged=$matches[4]
[([0-9]{4})/([0-9]{1,2})/([0-9]{1,2})/?$] => index.php?year=$matches[1]&monthnum=$matches[2]&day=$matches[3]
[([0-9]{4})/([0-9]{1,2})/feed/(feed|rdf|rss|rss2|atom)/?$] => index.php?year=$matches[1]&monthnum=$matches[2]&feed=$matches[3]
[([0-9]{4})/([0-9]{1,2})/(feed|rdf|rss|rss2|atom)/?$] => index.php?year=$matches[1]&monthnum=$matches[2]&feed=$matches[3]
[([0-9]{4})/([0-9]{1,2})/page/?([0-9]{1,})/?$] => index.php?year=$matches[1]&monthnum=$matches[2]&paged=$matches[3]
[([0-9]{4})/([0-9]{1,2})/?$] => index.php?year=$matches[1]&monthnum=$matches[2]
[([0-9]{4})/feed/(feed|rdf|rss|rss2|atom)/?$] => index.php?year=$matches[1]&feed=$matches[2]
[([0-9]{4})/(feed|rdf|rss|rss2|atom)/?$] => index.php?year=$matches[1]&feed=$matches[2]
[([0-9]{4})/page/?([0-9]{1,})/?$] => index.php?year=$matches[1]&paged=$matches[2]
[([0-9]{4})/?$] => index.php?year=$matches[1]
[[0-9]{4}/[0-9]{1,2}/[^/]+/attachment/([^/]+)/?$] => index.php?attachment=$matches[1]
[[0-9]{4}/[0-9]{1,2}/[^/]+/attachment/([^/]+)/trackback/?$] => index.php?attachment=$matches[1]&tb=1
[[0-9]{4}/[0-9]{1,2}/[^/]+/attachment/([^/]+)/feed/(feed|rdf|rss|rss2|atom)/?$] => index.php?attachment=$matches[1]&feed=$matches[2]
[[0-9]{4}/[0-9]{1,2}/[^/]+/attachment/([^/]+)/(feed|rdf|rss|rss2|atom)/?$] => index.php?attachment=$matches[1]&feed=$matches[2]
[[0-9]{4}/[0-9]{1,2}/[^/]+/attachment/([^/]+)/comment-page-([0-9]{1,})/?$] => index.php?attachment=$matches[1]&cpage=$matches[2]
[([0-9]{4})/([0-9]{1,2})/([^/]+)/trackback/?$] => index.php?year=$matches[1]&monthnum=$matches[2]&name=$matches[3]&tb=1
[([0-9]{4})/([0-9]{1,2})/([^/]+)/feed/(feed|rdf|rss|rss2|atom)/?$] => index.php?year=$matches[1]&monthnum=$matches[2]&name=$matches[3]&feed=$matches[4]
[([0-9]{4})/([0-9]{1,2})/([^/]+)/(feed|rdf|rss|rss2|atom)/?$] => index.php?year=$matches[1]&monthnum=$matches[2]&name=$matches[3]&feed=$matches[4]
[([0-9]{4})/([0-9]{1,2})/([^/]+)/page/?([0-9]{1,})/?$] => index.php?year=$matches[1]&monthnum=$matches[2]&name=$matches[3]&paged=$matches[4]
[([0-9]{4})/([0-9]{1,2})/([^/]+)/comment-page-([0-9]{1,})/?$] => index.php?year=$matches[1]&monthnum=$matches[2]&name=$matches[3]&cpage=$matches[4]
[([0-9]{4})/([0-9]{1,2})/([^/]+)(/[0-9]+)?/?$] => index.php?year=$matches[1]&monthnum=$matches[2]&name=$matches[3]&page=$matches[4]
[[0-9]{4}/[0-9]{1,2}/[^/]+/([^/]+)/?$] => index.php?attachment=$matches[1]
[[0-9]{4}/[0-9]{1,2}/[^/]+/([^/]+)/trackback/?$] => index.php?attachment=$matches[1]&tb=1
[[0-9]{4}/[0-9]{1,2}/[^/]+/([^/]+)/feed/(feed|rdf|rss|rss2|atom)/?$] => index.php?attachment=$matches[1]&feed=$matches[2]
[[0-9]{4}/[0-9]{1,2}/[^/]+/([^/]+)/(feed|rdf|rss|rss2|atom)/?$] => index.php?attachment=$matches[1]&feed=$matches[2]
[[0-9]{4}/[0-9]{1,2}/[^/]+/([^/]+)/comment-page-([0-9]{1,})/?$] => index.php?attachment=$matches[1]&cpage=$matches[2]
[([0-9]{4})/([0-9]{1,2})/comment-page-([0-9]{1,})/?$] => index.php?year=$matches[1]&monthnum=$matches[2]&cpage=$matches[3]
[([0-9]{4})/comment-page-([0-9]{1,})/?$] => index.php?year=$matches[1]&cpage=$matches[2]
[.?.+?/attachment/([^/]+)/?$] => index.php?attachment=$matches[1]
[.?.+?/attachment/([^/]+)/trackback/?$] => index.php?attachment=$matches[1]&tb=1
[.?.+?/attachment/([^/]+)/feed/(feed|rdf|rss|rss2|atom)/?$] => index.php?attachment=$matches[1]&feed=$matches[2]
[.?.+?/attachment/([^/]+)/(feed|rdf|rss|rss2|atom)/?$] => index.php?attachment=$matches[1]&feed=$matches[2]
[.?.+?/attachment/([^/]+)/comment-page-([0-9]{1,})/?$] => index.php?attachment=$matches[1]&cpage=$matches[2]
[(.?.+?)/trackback/?$] => index.php?pagename=$matches[1]&tb=1
[(.?.+?)/feed/(feed|rdf|rss|rss2|atom)/?$] => index.php?pagename=$matches[1]&feed=$matches[2]
[(.?.+?)/(feed|rdf|rss|rss2|atom)/?$] => index.php?pagename=$matches[1]&feed=$matches[2]
[(.?.+?)/page/?([0-9]{1,})/?$] => index.php?pagename=$matches[1]&paged=$matches[2]
[(.?.+?)/comment-page-([0-9]{1,})/?$] => index.php?pagename=$matches[1]&cpage=$matches[2]
[(.?.+?)(/[0-9]+)?/?$] => index.php?pagename=$matches[1]&page=$matches[2]