You will insure the cars based on where they are driven the most. If you drive more in one state, insure the car there.
Can one person have two car insurance policies on two different cars
Certainly.
Yes, but why do you have 4 cars any way.
To do this you can go to an insurance website such as admiral which gives you a discount on your second car
The same way you insure one car. It is not that unusual for a person to own two vehicles. This is where it pays to have a local agent that you can go in and speak with. An on line company where you never speak with the same person twice is not the way to go with insurance. The car that you normally drive to work or school will be rated as such and the second vehicle will be rated as an extra vehicle with pleasure use. Be truthful and if someone else drives the car even occasionally tell your agent.
Only human beings are covered by disability insurance. If you want to insure cars, you require automobile insurance.
No. You cannot insure a vehicle that you do not own. The exception would be in a family situation where two spouses own two vehicles and insure them on one policy.
You can do it. Just tell your insurance company. Its exactly the same as insuring one car, it will cost a little more im sure but that's about the only difference.
In the UK it would depend on the insurance company's policy. Get several quotes, explain what you need.
Each individual car a person owns is required to have its own policy.
Yes, It is usually cheaper to have 2 vehicles on the same policy but there may be some cases where you need to have them separated. Some companies will not insure classic cars correctly, recreational vehicles. or motorcycles so they would need a separate policy for a separate company.