Is auto-entrepreneur the best option to run a gite business?

We are intending to move to France next year and are looking at buying an existing business with gites and bed and breakfast. In addition to that my wife and I will offer artisan services to guests and visitors - they will be the minority part of the business in financial terms. We are intending to operate the business as an Auto-Entrepreneur and I believe that this will be registered as an Activite Commerciale.  Am I correct in sating that cotisation charges on this type of business would be 12% of turnover?

I am 59 and my wife is 53. We will both have paid sufficient UK contributions to get state pensions - at the due time. Is there any reason for tax or social charges purposes for it to be better that one of us is the auto-entrepreneur than the other? We would not be conjoint because of the additional cotisation payment required but would add the other as a dependent when registering the business. In addition to the income generated from the French business we will have income from letting a property in the UK as well as investment income. The letting income from the UK would not be considered as part of the French business would it? I assume that we do not pay social charges on the investment income?