Can you advise me on a business plan?

I am thinking of investing in buying an existing salon de coiffure, as an investment, and would like to know what the pitfalls and risks are. I have a friend who is a qualified coiffeuse with qualification to manage and run a salon de coiffure, and it is because of her that I would like to help by such an investment. The reason for the sale is because the current owner’s qualified coiffeuse wife passed away last year and the salon is not making enough turnover without such a Gerant. I have obtained details of the two salaried staff (contrat indeterminée), the bail and accounts for the years 2011, 2012 and 2013.

I passed on all these documents to my friend for her to make her business plan and come up with her scenario of enhanced turnover based on her own input (her retained clients from her current freelance work) plus the current turnover by the current two salaried staff at the salon. Once I receive her business plan, I need to analyse it and determine whether it is a viable plan that allows her to manage the salon as an independent gerant, with her paying me a lump sum or a percentage of turnover per month.

The salon is fully equipped, and the asking fond de commerce price is around 75K euros, but I think it is worth much less.

1. Can you help in assessing such a business plan and provide me with an analysis of risks involved, etc?
2. Can you advise me what is the amount to offer the current owner?
3. If the work did not pick up and my friend quits, am I lumbered with the whole salon and have to continue paying the two current salaried staff?
4. Can we discuss over the phone?