1) You can’t/shouldn’t use all three caching plugins together. It’s not a good idea. Also, You’ll most likely need to ask Bluehost about how they have tuned there servers.
2) Adjusting settings within a caching plugin alone isn’t going to drop load times. You’ll need to combine multiple techniques such as image optimization ( you should be using optimized images ), serving static content from a content delivery network, script/style minification (which is mostly taken care of by the caching plugin) , placing render blocking js/css in the header and all others in the footer… etc.
These are just a few techniques. I would recommend using a site such as http://www.webpagetest.org/ and http://tools.pingdom.com/fpt/ to test/re-test your adjustments.
It takes quite a while to fine tune a site, and it’s an acquired skill. It’s not as easy as flipping a switch unfortunately.
Have a look at the first link I provided, it will help pin point where your bottle necks are, and give you a few tips on how to minimize load times.
You shouldn’t need a caching plugin on the Optimized Hosting for WordPress plan as it has varnish cache installed on the server. If you’re having load speeds that high it could be that your internet connection is having some congestion along the line. It could also be that your site isn’t quite optimized. Too many or poorly coded plugins can really bog a server down. Poorly coded themes will do the same.
“1) You can’t/shouldn’t use all three caching plugins together. It’s not a good idea. Also, You’ll most likely need to ask Bluehost about how they have tuned there servers.”
@ Evan Herman Good advice. You’re eventually going to see a conflict and/or give yourself something else to manage or remember.
@mdwilkins voldemortensen’s mention of too many plugins is spot on. How many plugins do you have installed? Too many will most certainly cause performance issues for your site.
