I can't believe that you would take off with the config warning blaring at you - it really is most distracting. Tripping the CB is a possibility, but it is akin to suicide, so I would rule this out.
A lower flap setting will generally mean longer on the runway, but a better climb, since AMS has a fairly long runway this is certainly a possibility, although a better climb would not be required since it is pretty flat around AMS.
In the 767-300 series, our normal take off settings are 5, 15 and 20. We certainly cannot take off at flaps 1 in my airline, but I think the 200 series can do (not sure as I don't fly it, but I do fly the 300ER). The 767 does not have flap 10, we have 1, 5, 15, 20, 25, 30.
25 and 30 are landing flap settings, with flap 20 as a single engine landing setting.
It is true that flap 1 does not move the TE flaps and that flap 5 is mostly rearwards movement rather than downwards movement.
411A - lots of airlines taxi with flaps set, it has been proven to reduce the number of incidents of attempted take off without flaps. Some still do set flaps during taxi, but not all that many.