I can help with the first bit LOL
Raining stair-rods = Raining very heavily.
This is a colloquial North of England expression. Stair-rods are the metal rods that hold stair-carpets in place on each step. The allusion is to rain which is so heavy as to appear like falling stair-rods.
& I think Toot's finger slipped with 'sipummer'
D