Strong smell of Gasoline?

Problem #1
when I dont have a full tank mostly. My car when I turn it on after just 2 minutes if parked the smell of gas is very bad especially when I have only 1/3 of a tank of gas or less. If at a stop at time I want to take off it chuggs and I have to pump on accelerator to get it going or it will turn off. Occasionally if at a red light for two long when car is stoped it has turned off at time I try to accelerate to take off.

problem #2
I have lots of problems to turn the key on (at starter switch) I would like my husband to replace it but need instructions. HELP!