How to create an IT startup in France?

I am a software developer and would like to establish my own software development company in France.

I would like to carry out the following activities under this company:

• Provide the following services:
  • Desktop application development.
  • Web application development.
  • Mobile app development.
• In addition to the above, the company will be involved in pure R&D activities with the purpose of creating software and hardware solutions related to the Aerospace industry. Please note, the development of any hardware is limited to prototyping and is not intended for mass production or sale.

With that said I would like to ask you the following questions:

1. Which type of company do you recommend that would allow me to undertake such activities?
2. Can I run the company from my home?
3. If I establish my own business will I have to communicate that to any of the tax or social security authorities or is that done during the process of creating the business? I am currently registered as unemployed with Impo.
4. I have also read on this website that I will be liable to the below charges:
   Social charges = 21.3%
   Contribution a la formation professionnelle = 0.2%
   Income tax (pay at end of year) =  (total turnover x 34%) x 2.2%
   Contribution foncière entreprise = 200 - 800 euros

Are those figures/estimations correct?