Image size for speed

Hey HulaSlim,
Thanks for your question, as I can tell from the Helper Lite for PageSpeed plugin page it

Speed up your site with attributes decoding=”async” & loading=”lazy” for <img> and <iframe>. Removes problem “Does not use passive listeners to improve scrolling performance”. Help to Up Your Google PageSpeed Insights Score.

so this is mostly to get a better PageSpeed Insights Score, the theme already has a lazy load option so the “async” attribute may help with PageSpeed Insights Score but not too much with overall load time, I don’t think that it would conflict with LiteSpeed, but I would disable it until after setting up LiteSpeed and getting a good load time.
I would recommend setting up LiteSpeed first and don’t add any other caching right away, as there may be a issue with supercache, since LiteSpeed works on your server it should work better, at least try it first.
The TinyPNG image compression plugin will work well with LiteSpeed and should help with image sizes.
You can also enable compression in your .htaccess file if you add this code to it:

<IfModule mod_deflate.c>
AddType x-font/woff .woff
AddOutputFilterByType DEFLATE image/svg+xml
AddOutputFilterByType DEFLATE text/plain
AddOutputFilterByType DEFLATE text/html
AddOutputFilterByType DEFLATE text/xml
AddOutputFilterByType DEFLATE text/css
AddOutputFilterByType DEFLATE text/javascript
AddOutputFilterByType DEFLATE application/xml
AddOutputFilterByType DEFLATE application/xhtml+xml
AddOutputFilterByType DEFLATE application/rss+xml
AddOutputFilterByType DEFLATE application/javascript
AddOutputFilterByType DEFLATE application/x-javascript
AddOutputFilterByType DEFLATE application/x-font-ttf
AddOutputFilterByType DEFLATE application/vnd.ms-fontobject
AddOutputFilterByType DEFLATE font/opentype font/ttf font/eot font/otf
</IfModule>

Best regards,
Mike