If I recall, on my Maximus board, it had me set at 104x42 before I had started my overclocks through BIOS on it. Strange, now that I think on it...
That is my understanding also, that it is best to manually set your voltages/offsets because automatic settings tend to be higher than needed.
My understanding is that those settings will not affect a manual overclock but you can customize those settings also (change advanced power setting). I really can't say from experience since I run mine 100%, 24/7 and keep all high performance settings enabled
The asus boards have an Asus AI suite utillity where if u do the automatic overclock labeld as "Fast" gives u the overclock you are runing at the moment.
Can be manually changed to default settings in bios.
Here is my system that runs same thing http://i45.tinypic.com/34sj7dt.jpg .