Thanks for the background on your issue, I've read through the above posts and threads. I also delved into our bug-reporting system and the issue you describe doesn't seem to be widespread, as we don't currently have any other reports on it.
I did some research on this error message:
SoftException in Application.cpp:641: Could not execute script error due to the high load
Some of the results I found point to limitations on HostGator's shared hosting servers, in multiple themes and even with other content-management systems, including Drupal. The threads all mention a limit on some HostGator servers of 25 concurrent processes.
Have you talked to HostGator about the possibility of increasing that limit for your account?
Do you have another account on a different server, with a different host on which you could test the site?
Unfortunately I don't have any alternative themes to recommend, but we are currently working on p2's successor, o2, in case you want to sign up: http://geto2.com/