Development Mode Cache Rule

It means Currently Development can active for 4 hours , after created cache rule to bypass development mode can last longer time
Correct above sentence

Here’s a corrected version of your sentence:

"Currently, Development Mode can only remain active for 4 hours. By creating a cache rule to bypass, you can extend the duration beyond this time."

Currently, Development Mode can only remain active for 4 hours. By creating a cache rule to bypass, you can extend the duration beyond for all time

"Currently, Development Mode can only remain active for 4 hours. By creating a cache rule to bypass, you can extend the duration indefinitely."

Now cloudflare we have created Cache rule to optimized clouflare cache to bypass edge clouflare cache that caused problem for css and js issues sometime
Correct above sentence

"Now, we have created a cache rule in Cloudflare to optimize its cache by bypassing the edge cache, which sometimes caused issues with CSS and JS."

Yes cloudlfare is still required we are other feaure of this like dns and other site accessable from anywhere
Correct above sentence

"Yes, Cloudflare is still required as we use other features like DNS management and ensuring the site is accessible from anywhere."

Regarding update
We have updated the php/mysql version , all the plugins and themes except avada theme
Correct above sentence

"We have updated the PHP/MySQL versions, as well as all plugins and themes, except for the Avada theme."

We have updated the PHP/MySQL versions, Worpdress Core,and as well as all plugins and themes, except for the Avada theme at that may there some new updates arrived becuase last time we have update since 1 month ago

"We have updated the PHP/MySQL versions, WordPress Core, and all plugins and themes, except for the Avada theme. There may be new updates available for it since it was last updated a month ago."