Hi oom and welcome to the forum. I went BR last month, and I know how stressful it is filling the forms out! I will try and answer your questions as best I can.
1/2. You will need to declare the car on the form. There is a section where you have to declare that you have sold the vehicle, and also a section where you state if you have use of a car that doesn't belong to you. You will also need to state the value of the car. Did you sell the car to your cousin for less than market value, and did you know you were going BR when you sold the car?
3. Don't worry about the bank and credit card statements. I didn't have mine, but the OR can apply to the banks and credit card companies for them.
4. You need to give the OR details of your employments and NI number. If you have a second job you will need to declare this.
Good luck!
Onwards and upwards!!!
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