johnybravo,
I have bought using this scheme through another company, the deal is exactly as you have explained, however the mortgage deferment is for a 2 year period, during this two year period my rent will gather in my french bank account this will be enough to cover any shortfall in the future, as long as you use a strong management company you are in a good position, you should speak with the company you are dealing with and see if there is a chance to get an interest only mortgage, where this is possible there is usually no shortfall with the mortgage repayments as the rental income is sufficient to cover payments. Also its worth bearing in mind that you have the rental guarantee for 9 years from the management company. I like you was a nervous investor and when I initially made the jump into the property market i was scared of every opportunity that was put in front of me.