As others have written, some of what you wrote may be a matter of wording in English. But since you're writing in English, please pay attention to the phrasing in the replies.
I'm a sighted person developing assistive technology for blind people, so I think I'll answer just the first two questions:
1. Blind people understand whatever you would, albeit by different means sometimes. Rather than being taken advantage of, the problem I hear from blind friends more often is that sighted people will do silly things out of ignorance that are meant to help but are actually annoying. For example, a friend of mine who is a white cane user in an urban area has people yelling "Careful!" at her when she passes by stairwells, even if there was no danger of her turning, walking several steps without her cane, and falling down the stairs. Or when she crosses a street, a sighted person may grab her elbow without asking and then try to "help" her across.
2. **Blind people ARE average people**. **Blind people ARE normal people.** Start there. What you might ask is "Have you ever been treated as if you were a sighted person?" since that's the only difference.
Questions 3 and 4 make sense for blind folks to answer.
Please see the "Other Resources" links in the right, such as the "FAQ for Sighted People," which I'll also paste here:
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