I can't answer 1 but 2=First, make sure you weather proof the house, than go from there and try anything you think is necessary in this situation.
If the gradient or slope is high then the water flow will go faster because suppose water is flowing down from a skateboard ramp, it would flow faster than water flowing throw a straight pipe.
Here's a picture I drew to help you!
Answer: Hydrocarbons enter the cell by dissolving in the lipid bilayer of the membrane.
Explanation: