solved and back

I was struggling from a month on webpagetest to get my website optimized which hosted on a shared server. Finally, I got it. Just check:
First byte: 0.707s
some time it was more slower
First byte:0.286s (without plugins enabled)
First byte:0.313s (with all plugins enabled)

Unabled to solve few. Please help!

What I did?
Just used cloudflare that tripled my site speed.

I donno how it works but if any-body would like to give some idea, if its safe or not?

Cloudflare is fine and used by a whole lot of sites. It looks like you are making your HTML cacheable for a short period so they are able to cache it on their servers (particularly if you do a lot of testing back-to-back).

For the remaining issues, creating an image sprite is going to be a manual process and require editing your template. The browser caching is being flagged because of the short cache time (4 hours). It’s possible that that could just be a setting in the .htaccess that you can change to make it longer.