[jambo]

Clutch switch:
If you can start the bike without the clutch pulled in this has been bypassed, perhaps by a previous owner, no idea how long you've had the bike.

From my own experience 1,100 rpm is low enough to cause issues stalling with a little clutch drag on downshifts. 1,500 is where I'd set it.

The fact you've changed your fork legs isn't an obvious pointer, but the fact you've said the fuel is old suggests you've not been riding it of late. It's got colder and a lower than ideal idle may have been fine in summer, but less OK now the temperature's dropped. If the clutch is not adjusted perfectly / dragging slightly these things all add up.

Jambo