That apache.conf looks normal. There are 2 now options left:
a) Something went wrong during unpacking of the zip file. Other users reported problems that were solved when they used a different unzip program (the data dir must be writeable etc.)
b) The apache module mod_rewrite is not installed. I found some QNAP related links for that, maybe they help ....
http://wiki.qnap.com/wiki/Mod_Rewrite
http://forum.qnap.com/viewtopic.php?t=3512