I upgraded FreeBSD 8.0-RELEASE amd64 to 8.1-RELEASE amd64 in our lab, LSWS 4.0.16 x86_64-freebsd6 package works fine.
Can you send the core file location again to bug@litespeed....? looks like we did not get it.
It is really up to the OS kernel, task scheduler, cannot be done with user land application.
Yes, Cloud Linux should be able to limit CPU usage at user level.
wswatch may cause trouble for shared hosting environment which need to apply configuration changes frequently.
For signal 15 issue, please send us the error log and lsws/logs/ap_cmd_param.log
Does the site fetch remote content from another server? It may cause PHP process blocking on network I/O for long time.
You can try "strace -tt -T -p <lsphp5_pid>", see if you can catch one error.