How to convert redirects from IIS web.config to Apache .htaccess?

Question

Apache HTTP Server

Hello.
In the process of migrating an ancient PHP site from Windows server + IIS to Linux + Apache + .htaccess, there was a need to translate several redirects from the IIS web.config format to Apache .htaccess.
I managed to rewrite a few of them myself, but there are some that I can’t handle.
Help me please.
web.config rules:

<rule name="Rule1" enabled="true" stopProcessing="true">
    <match url="^switch\.php$" />
    <conditions>
        <add input="{REQUEST_METHOD}" pattern="^POST$" negate="true" />
        <add input="{QUERY_STRING}" pattern="^lang=([^=&amp;]+)$" />
    </conditions>
    <action type="Redirect" url="switch/{C:1}" appendQueryString="false" />
</rule>
<rule name="Rule2" enabled="true" stopProcessing="true">
    <match url="^switch/([^/]+)/?$" />
    <conditions>
        <add input="{REQUEST_FILENAME}" matchType="IsFile" negate="true" />
        <add input="{REQUEST_FILENAME}" matchType="IsDirectory" negate="true" />
    </conditions>
    <action type="Rewrite" url="switch.php?lang={R:1}" />
</rule>
<rule name="Rule3" stopProcessing="true">
    <match url="^zone-client/index\.php$" />
    <conditions>
        <add input="{REQUEST_METHOD}" pattern="^POST$" negate="true" />
    </conditions>
    <action type="Redirect" url="zone-client/index" appendQueryString="false" />
</rule>
<rule name="Rule4" stopProcessing="true">
    <match url="^zone-client/index$" />
    <conditions>
        <add input="{REQUEST_FILENAME}" matchType="IsFile" negate="true" />
        <add input="{REQUEST_FILENAME}" matchType="IsDirectory" negate="true" />
    </conditions>
    <action type="Rewrite" url="zone-client/index.php" />
</rule>
<rule name="Rule5" stopProcessing="true">
    <match url="^index\.php$" />
    <conditions>
        <add input="{REQUEST_METHOD}" pattern="^POST$" negate="true" />
        <add input="{QUERY_STRING}" pattern="^slug=([^=&amp;]+)$" />
    </conditions>
    <action type="Redirect" url="{C:1}" appendQueryString="false" />
</rule>
<rule name="Rule6" stopProcessing="true">
    <match url="^([^/]+)/?$" />
    <conditions>
        <add input="{REQUEST_FILENAME}" matchType="IsFile" negate="true" />
        <add input="{REQUEST_FILENAME}" matchType="IsDirectory" negate="true" />
    </conditions>
    <action type="Rewrite" url="index.php?slug={R:1}" />
</rule>
<rule name="Rule7" stopProcessing="true">
    <match url="^index\.php$" />
    <conditions>
        <add input="{REQUEST_METHOD}" pattern="^POST$" negate="true" />
        <add input="{QUERY_STRING}" pattern="^slug=([^=&amp;]+)&amp;details=([^=&amp;]+)$" />
    </conditions>
    <action type="Redirect" url="{C:1}/{C:2}" appendQueryString="false" />
</rule>
<rule name="Rule8" stopProcessing="true">
    <match url="^([^/]+)/([^/]+)/?$" />
    <conditions>
        <add input="{REQUEST_FILENAME}" matchType="IsFile" negate="true" />
        <add input="{REQUEST_FILENAME}" matchType="IsDirectory" negate="true" />
    </conditions>
    <action type="Rewrite" url="index.php?slug={R:1}&amp;details={R:2}" />
</rule>

My (over) attempts to rewrite them in .htaccess:

#Rule1
RewriteCond %{REQUEST_METHOD} !POST
RewriteRule ^translation\.php(.*) /translation? [R=302,L]
#Rule2
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^translation(.*) /translation.php [R=302,L]
#Rule3
RewriteCond %{REQUEST_METHOD} !POST
RewriteCond %{QUERY_STRING} ^lang=&$
RewriteRule ^switch\.php(.*) /switch/%1 [R=302,L,B]
#Rule4
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^zone-client/index(.*) /zone-client/index.php [R=302,L]
#Rule5
RewriteCond %{REQUEST_METHOD} !POST
RewriteCond %{QUERY_STRING} ^slug=&$
RewriteRule ^index\.php(.*) /%1 [R=302,L,B]
#Rule6
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^(.*)/?$ /index.php?slug=$1 [R=302,L]
#Rule7
RewriteCond %{REQUEST_METHOD} !POST
RewriteCond %{QUERY_STRING} ^^slug=&;details=&$
RewriteRule ^index\.php(.*) /%1/%2 [R=302,L,B]
#Rule8
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^(.*)/(.*)/?$ /index.php?slug=$1&details=$2 [R=302,L]