Hello Lukas
I could have been interested as I worked as a Project Manager in the UK (managing high risk multi-million pound projects). I have also managed two building projects here and have just signed a Contract for a third one. However, I thought your proposal to be very well reasoned and presented very professionally. I think though that you need to think about three aspects.

I'm not sure that I agree with you that the housing market in the Algarve is bouyant. There are thousands of villas/apartments for sale here. It is definitively a buyers market. Owners are dropping prices by as much as 25% in order to sell when they become desperate.
See you again