Thanks for your letter,
If everybody investing in Spain from abroad were half as sensible as you are then we would hear so many complaints and troubles.
You are right, that is not the Spanish Way, it seems that it is the Murcian Way, just don’t follow that way. Get a good lawyer in the area ( perhaps Juan Bertomeu can recommend you one ) who is honest enough to be strict with the developer, The alternative: buy in other region of Spain, as clear as that.
Oh, and those documents are just an example, there are others to check of course.
Jose Maria Sánchez Alfonso
Lawyer / Abogado
Málaga, Costa del Sol