By asking these questions, you will know whether you are dealing with an honest and ethical company or not. If you don't feel comfortable with the answers you receive, DO NOT hire that company. Find another company that can answer these questions to your satisfaction.
...And be sure to watch out for the following:
The bait and switch outfits that lure you in with cheap advertising. These are what we call Rip-Off Cleaners scamming unsuspecting homeowners for big dollars. They offer cheap cleaning services in their ads, but once they arrive in your home it is a completely different ball game. They explain that the quoted price was only meant for 'some' types of windows that you don't have. Or the price only included basic cleaning, and you need the more expensive cleaning. And they may do an unauthorized add-on service and try to make you pay for it.