Stop .htaccess rules to be carried over - .htaccess

Question

I am fighting on one Domain already quite a while with its .htaccess rules. I have found the rules I needed to redirect all non-existing files and folders and got it to work after i change its position in the .htaccess to top, so that my .htaccess looks now like this:
<IfModule mod_rewrite.c>
RewriteEngine on
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.*)$ / [R=301,L]
</IfModule>
#Rewrite for non www
RewriteCond %{HTTP_HOST} !^www\.
RewriteRule ^(.*)$ http://www.%{HTTP_HOST}/? [R=301,L]
<ifModule mod_gzip.c>
mod_gzip_on Yes
mod_gzip_dechunk Yes
mod_gzip_item_include file .(html?|txt|css|js|php|pl)$
mod_gzip_item_include handler ^cgi-script$
mod_gzip_item_include mime ^text/.*
mod_gzip_item_include mime ^application/x-javascript.*
mod_gzip_item_exclude mime ^image/.*
mod_gzip_item_exclude rspheader ^Content-Encoding:.*gzip.*
</ifModule>
RewriteEngine On
RewriteCond %{HTTP_USER_AGENT} acer|alcatel|amoi|android|asus|avantgo|benq|blackberry|blazer|boxee|bravia|cdm-|ce-html|compal|(core|gom|m|vlcmedia|windows-media)player|dlna|docomo|dreambox|elaine|ericsson|fennec|flycast|foobar2000|google\ wireless\ transcoder|googlebot-mobile|googletv|gt-|hbbtv|hiptop|htc|huawei|iemobile|im-|ipad|ipaq|iphone|ipod|iris|itunes|kindle|large|lg(-|\/|_|1|2|3|4|5|6|7|8|9|e|http)|lenovo|levis|maemo|midp|miro|mmp|mot-|mobile|motorola|msn.*tv|mtv|nettv|nexus|nintendo|nokia|opera\ (mobi|mini)|palm|panasonic|pantech|pg-|philips|pixi\/|playstation|plex|plucker|pocket|portalmmm|pre\/|psp|quicktime|qtek|rim|sagem|samsung|sanyo|sch-|screen|sec-sgh|sendo|sfr|sgh-|sharp|sie-|smart(hub|phone|.?tv)|sonyericsson|sph-|sprint|spv|swisscom|symbian|t-mobile|tablet|toshiba|touch|treo|upnp|up.browser|vertu|videoweb|vk-|vodafone|volksbox|wafa|wap|webos|webtv|wii|windows\ (ce|phone)|wml|wonu|xbmc|xbox|xda|xiino|zte|zune [NC]
RewriteRule ^(.*)$ http://www.domain.tld/m/ [L,R=302]
## EXPIRES CACHING ##
<IfModule mod_expires.c>
ExpiresActive On
ExpiresByType image/jpg "access 1 year"
ExpiresByType image/jpeg "access 1 year"
ExpiresByType image/gif "access 1 year"
ExpiresByType image/png "access 1 year"
ExpiresByType text/css "access 1 month"
ExpiresByType text/html "access 1 month"
ExpiresByType application/pdf "access 1 month"
ExpiresByType text/x-javascript "access 1 month"
ExpiresByType application/x-shockwave-flash "access 1 month"
ExpiresByType image/x-icon "access 1 year"
ExpiresDefault "access 1 month"
</IfModule>
## EXPIRES CACHING ##
<IfModule mod_deflate.c>
<filesMatch "\.(js|css|html|php|jpg|jpeg)$">
SetOutputFilter DEFLATE
</filesMatch>
</IfModule>
My problem is that my subfolders would need its own redirect rules for non-existing files/folders. I do not want them to be redirected to the root, but rather to their correct index'folder'.
The Site is build like this:
http://www.domain.tld/ <-- Mainsite
http://www.domain.tld/keywordX/1/ <-- Index folder for keyword X
http://www.domain.tld/keywordY/1/ <-- Index folder for keyword Y
http://www.domain.tld/keywordZ/1/ <-- Index folder for keyword Z
After I had added the rules to redirect all non-existing files/folders from root it also redirects my non existing files/folders in the Subfolders to the root too.
I have change the First Part of my .htaccess afterwards in a way i found to exclude directories, but that ended in a redirect error:
<IfModule mod_rewrite.c>
RewriteEngine on
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(keywordX|keywordY|keywordZ)($|/) - [L]
RewriteRule ^(.*)$ / [R=301,L]
</IfModule>
Any suggestion how i can avoid this behavior?
The following i have tried to add in the htaccess in /keywordX/ folder as also in the /keywordX/1/ folder:
I had found that adding an "RewriteEngine On" would do the trick. But it didn't.
I found that Line 1 RewriteEngine Off and Line 2 RewriteEngine On would work, but it also didn't.
Update 3:
The first time the site is loading properly AND the most redirects for the root are working. All existing folders are NOT redirected (No idea why it is not redirecting them as they are not excluded), but so far kproxy shows me kategoryX/kategoryY/kategoryZ are loading as they should.
It looks like i was with my previous tryouts on the right path, just that my file exclusion was incorrect. But after more and more reading and slowly but steadily getting more angry, i stumbled upon file extension exclusion.
RewriteEngine On
RewriteCond %{REQUEST_URI} !^/(images)/ [NC]
RewriteCond %{REQUEST_URI} !\.(xml|txt|css)$
RewriteRule ^.+$ / [R=302,NC,L]
With this bit of Code i was able to redirect all incorrect FOLDER request back to root.
What now is missing, is a redirect for incorrect files (what are the major part of the redirects) ... files like 123_itemname.html, 456_itemname.html and so on.
Is there a way to extend the htaccess code that i am using right now, or do i need to have a complete new approach?
Edit: I have made a lot of editing to the Question as i just couldn't wait and let someone else figure out whats wrong.