What would be the use of one degree of flaps? And is there any reason to use both flaps and spoilers combined?
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.
Setting your flaps to 1 degree increases lift slightly, but also doesn't cause too much drag because its only set to 1 degree. The flaps and the spoilers are used for landing. The design of the flap is too increase lift but also increase drag. So it comes in nice and slow, but has plently of lift. The spoilers are used for when the plane touches the runway. They flip up to cause drag which helps slow down the plane. Spoilers can also be used if the plane is going to fast in midair, which I have seen pilots flip up the spoilers because the approach was a little bit too quick. Both are used during landing.
As mentioned in other answer, you use the flaps to put the wings in a configuration where, at the cost of more drag, they increase lift; this allows the aircraft to fly a bit slower.
The spoilers, on the other hand, are used as a temporary measure to decrease lift and increase descent. So, basically, in approach you would have your flaps in a fixed position, and eventually would use the spoilers for a short time to adjust the glide path (i.e, "I'm coming too high").