What is the purpose of extending one degree of flaps (perhaps with spoilers)?
Normally, one degree of flaps in fact only translates to an extension of the leading edge devices (e.g. slats), trailing edge flaps remain fully retracted. 

On some aircraft this configuration can be used for take-off.

Combination of flaps and spoiler is for example used in slow flight on steep descends. The flaps ensure that the wing doesn't stall, the spoilers dump part of the lift and act as airbrakes to keep the speed under control.