How do we start a tourism business in France?

I am exploring the possibility of setting up a new business that enables me and my wife to do various business activities under one umbrella company. The business we are thinking of starting with involves arranging for inward tourism by identifying activities that has appeal to many groups (such as hiking, sightseeing, skiing, etc.). We intend to work from home and therefore minimise initial costs.

1. Do we need a legal entity to be set up,  and if so in what form?
2. Can I set up this entity? Alternatively, can you help in setting it up?
3. Is there a need to register with a tourist board, chamber of commerce, etc?
4. Are there tax implications and if so which ones? I am a British retiree living in France and my wife does not work.
5. Do we need to take up business insurance for this activity?
6. Do we need to set up a website, and if so how do we go about it?
7. Is there a register that we can access to identify potential service providers such as hiking guides, bus companies, etc.
8. We are planning to be the organising intermediaries for these activities and plan to package activities for say 5 day, 7 day or 10 day periods and attempt to market them to our family, friends and oversees to other people. What is normally the markup percentage on actual costs incurred?