A totally there have been successful ICO's. Like venture capitalism they are far from a sure investment. Big reward requires big risk. ETH is a pretty strong crypto.
Off of the top of my head there was a dairy farm that used it. All an ICO does is invest in a business. If the business succeeds then they can pay a return.
Not at the moment. Maybe after work I could do a quick search. I noticed some videos about successful ICO's on YouTube with a search. Didn't watch any to see if they were worth linking
I think the ICO token works like a share of the company. One you can sell to others, or back to the company. If the business goes bust there is nothing to pay back.