In general OLS is faster than Apache. However it is not full functionality as LS. OLS is essentially a carrot to hope you will buy LS.1- OpenLightSpeed or,
Apache option 2 is fine and well used and tested.2- Apache and:
apache + php-fpm
Ioucube
Opache
I would only do this if you are sure of your resources on your server. If not you could overload the server if you dont do the proper calculations3- Extend connections in php-fpm
vi /usr/local/directadmin/conf/directadmin.conf
php_fpm_max_children_default=1000
Not in case you have Litespeed Pro with LS Cache Plugin (this really rules them all) & Redis & OpCacheWP Rocket is the one WordPress performance plugin to rule them all.