Allowance for starting a consultancy business in France?

I am resident in France and have paid income tax in France for the last two years. Prior to that I was paying it in the UK and declaring it here as I worked for a UK based company. I will become unemployed on the 7 October following Rupture Conventionnelle from my contrat de travail à durée indéterminée (CDI) and wish to set up my own consultancy business. I anticipate that my initial business customers will be UK based, although I am hopeful that there will be a number of EU customers in due course. Most of the work will be from my home, with trips to meet customers as and when required.

1. Am I correct in assuming that, as I will soon register as unemployed, the state makes some allowance for starting a new business in France?
2. For a company providing consultancy services do I need to obtain any specific licence to operate?
3. If I have UK customers, is there a way for a France based business to charge them in GBP rather than in euros?
4. Can I initially start as an auto-entrepreneur business and then once the business is properly established change the structure?

I would be really grateful if you can initially provide guidance regarding these.