Contrary to the sellers' and their super sales_conscious agents' familiar claim that "There is nothing to lose in signing those documents," quite the complete opposite is true _ namely, a great deal, in fact, could potentially be lost particularly by the buyer by signing an LOI to a supposed seller. Why? In a word, this is because the LOI is actually fraught with many incalculable legal flaws, traps and pitfalls, much of which could often be prohibitively costly for the buyer, according to legal authorities and contract law experts. (See below for more on this)
Even taken at their word, it doesn't change the fact that they are using documentary procedures that are unusual, and abnormal. Contact any business college, or speak to established traders or people working for large multinational corporations. Talk directly to international bankers on this.