Do we have to deactivate the official Cloudflare plugin in order to use your plugin effectively?
– Yes if you choose to use this plugin you need to make sure that you have removed the official Cloudflare plugin from your site and also APO is disabled inside Cloudflare Dashboard.
also do we have to change the nameservers to Cloudflare’s nameservers?
– Yes to use Cloudflare your domain nameserver should point to the nameservers given by Cloudflare.
Can we use it alongside Wp-rocket. I don’t think so but your inputs are required to confirm?
– Yes but only for static file optimization. You cannot use more than one page caching system on a site. So, if you like to sue WP Rocket you need to make sure all page caching options are disabled inside WP Rocket and it is only being used for static file optimization.
Keep in mind that Wp-rocket has its own API integration with Cloudflare and you do too so i guess this is why this would not be a good idea.
– There is no special API integration. With WP Rocket + CF integration your static files will be provided over Cloudflare CDN which is done anyway when you use Cloudfare on a site. While this plugin will make sure that both your HTML type request and static files are served over CF CDN. My personal suggestion would be if you absolutely need WP Rocket then only use it otherwise there are many other great plugins out there for static file optimization.