WordPressの.htaccess編集は3つだけでOK

# BEGIN LSCACHEの上に以下のコードをコピペしてください。

<!-- SSLリダイレクト設定 -->
<IfModule mod_rewrite.c>
RewriteCond %{HTTPS} off
RewriteRule ^(.*)$ https://%{HTTP_HOST}%{REQUEST_URI} [R,L]
</IfModule>

<!-- URLの正規化 -->
Options +FollowSymLinks
RewriteEngine on
RewriteCond %{HTTP_HOST} ^www\.kagesai\.net$
RewriteRule ^(.*)$ https://kagesai.net/$1 [R=301,L]
RewriteCond %{THE_REQUEST} ^.*/index.html
RewriteRule ^(.*)index.html$ https://kagesai.net/$1 [R=301,L]

<!-- プライマリドメインから独自ドメインへ -->
RewriteCond %{HTTP_HOST} ^kagesai\.プライマリドメイン\.〇〇\.〇〇$ [NC]   
RewriteRule (.*) https://kagesai.net/$1 [R=301,L]
RewriteCond %{HTTP_HOST} ^www\.kagesai\.プライマリドメイン\.〇〇\.〇〇$ [NC]
RewriteRule (.*) https://kagesai.net/$1 [R=301,L]
<!-- ここまで -->

<!-- ログインURL変更 -->
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteRule ^enter/?$ /wp-login.php?abcd1234 [R,L]
RewriteCond %{HTTP_COOKIE} !^.*wordpress_logged_in_.*$
RewriteRule ^dashboard/?$ /wp-login.php?abcd1234&redirect_to=/wp-admin/ [R,L]
RewriteRule ^dashboard/?$ /wp-admin/?abcd1234 [R,L]
RewriteRule ^register/?$ /wp-login.php?abcd1234&action=register [R,L]
RewriteCond %{SCRIPT_FILENAME} !^(.*)admin-ajax\.php
RewriteCond %{HTTP_REFERER} !^(.*)https://kagesai.net/wp-admin
RewriteCond %{HTTP_REFERER} !^(.*)https://kagesai.net/wp-login\.php
RewriteCond %{HTTP_REFERER} !^(.*)https://kagesai.net/enter
RewriteCond %{HTTP_REFERER} !^(.*)https://kagesai.net/dashboard
RewriteCond %{HTTP_REFERER} !^(.*)https://kagesai.net/register
RewriteCond %{QUERY_STRING} !^abcd1234
RewriteCond %{QUERY_STRING} !^action=logout
RewriteCond %{QUERY_STRING} !^action=rp
RewriteCond %{QUERY_STRING} !^action=register
RewriteCond %{QUERY_STRING} !^action=postpass
RewriteCond %{HTTP_COOKIE} !^.*wordpress_logged_in_.*$
RewriteRule ^.*wp-admin/?|^.*wp-login\.php /not_found [R,L]
RewriteCond %{QUERY_STRING} ^loggedout=true
RewriteRule ^.*$ /wp-login.php?abcd1234 [R,L]
</IfModule>