IMHO, when an invalid value is provided, Hipache should refuse to start.
Also, I think that the mode parameter should be mandatory (and allow values file/syslog/none).
Otherwise, it's easy to forget the value (or make a typo) and not see any kind of output and wonder "hey what's going on?"
Last but not least, a stdout option would be relatively easy and useful to add.

I'll let @samalba decide what is the better solution.