The export laws do apply to software. I know with cPanel, since that company is headquartered in the US, therefore US export laws applied to us providing access to their software that we were running. Even though the software never leaves our US based servers, allowing people from countries that the government of the country of origin of the software decides if it can be "exported" even if there is no money changing hands, such as free hosting.
Plesk is headquartered in Canada so I would assume it is Canadian export laws that would decide whether Syrians can use Plesk or not. Canada has also eased sanctions on Syria starting in March of this year, so I think Canada would be ok with us "exporting" their software to Syria. Plus there is precedent of other Syrian websites and webhosting companies are already using Plesk.
The Canadian general permit is valid until August 25th of this year, and it may or not be renewed at that time. Likewise, the US agreement tentatively ends on December 2nd, but could be revoked at any time.
Yep, definitely.
Sure, but if either Canada, the origin of some of our software, or the US, the origin of our hardware, changes the rules again we will need to suspend all Syrian accounts immediately. You should be able to create an account now.