[NiteWave]

>Does this constitute as file download or something else?
should be file download

>The cores which are being used by LSWS - are they also available for php processing if needed?
yes. actually it's decided by kernel.

to enable lsws page cache for vBulletin, need 2-CPU(or above) license. between 2/4/8-CPU license, which is best for your site and traffic, depending on many other factors. you can switch between these licences, to watch the performance for a few days, to get the best answer from yourself.

for upgrade/downgrade license,please refer:
http://www.litespeedtech.com/support...ngrade_license