As far as I know, OLS is serverwide. So it's not like we are reseller and add a site. It's like we either use apache or OLS.
For the rest I don't know, we don't use OLS.
Its very easy :
/build set webserver openlitespeed
./build set php1_mode lsphp
./build set php1_release your num of php
./build openlitespeed
./build php n
./build rewrite_confs