The company you are renting the bus from should have the insurance. You do not need to purchase insurance from a separate company.
Non Owners auto insurance does not cover rental cars at all. You will need to buy insurance from the rental car company to be covered.
No, you would need to purchase an Insurance policy for your Rental Property. Sometimes referred to as landlords Insurance.
Find out first if your own insurance will cover you in the rental care. If so, you don't need rental insurance. Also, it is wise to take the time to choose the type of rental insurance you want should you decide to purchase it. Here is some good reading information on that: http://www.foxbusiness.com/personal-finance/2011/06/22/rental-car-insurance-is-it-worth-price/
Some auto insurance policies transfer to rental cars, and some do not. You need to ask your insurance agent about the details of your insurance policy, and the specifics of coverage while you are driving a rental car.
You will need rental property insurance if your are the owner of a rented property. This insurance, in addition to standard household insurance, covers things such a public liability.
You are not required to purchase insurance from a rental car company. However you are required by law to have insurance. If you have your own insurance call your insurance company and ask what they cover for rental cars, then once you get to the rental car company ask them what their insurance covers, then use which ever one you feel is best for you. If you do not have personal insurance, I would definitely take out the rental cars insurance.
Check you policy to determine if you have rental car insurance. Some credit cards also have rental car insurance. http://www.theglobeandmail.com/globe-investor/personal-finance/home-cents/do-you-need-rental-car-insurance/article1994097/
You buy rental car insurance so if you are in an accident your insurance will pay for part or all of rental car expenses if a rental car is needed. Without this insurance this will be out of pocket for you.
You do not necessarily need rental car insurance. If you have comprehensive or collision insurance you may not need what the rental car company is suggesting.
If you already have full coverage auto insurance, there is no need to purchase additional insurance for your rental car. The only event where you would need the insurance from EZ Car Rental, was if you were to get into an accident, they would cover the cost of the time lost for the rental. If you don't purchase their insurance and get into an accident, you will have to pay for the days they are out money for not being able to rent the car out.
To find the best car rental rates, you should evaluate exactly what type of car and services you need. You can easily cut the cost of your car rental quite a bit if you find that you do not need the car insurance on the rental car because your regular car insurance company or credit card company provides insurance coverage for the rental.
You can and you actually need to.