Here is the best plugin you will ever need to load JS and CSS asynchronously, and improve Google pagespeed which in turn will help you rank better. Google uses pagespeed as one of the factors in
Google does demote non-mobile friendly smartphone sites from ranking so well on mobile. It is for your own good that you make your site responsive and test it before Google does.
If you are getting this twitter error "oops spammy link" then your site is most likely in the Spamhause database. You can go to the Spamhause website and fill out the removal form to get your site removed