Munkeh
A persuasive case, and history has proved you right time and again about the often (but not always) illusory advantage of beating your competitor to market by a year or two.
But your assumption that "The A350 simply will not be released to the market unless it betters the 7E7 and coming from behind, Airbus will be in the perfect position to ensure that it does" presupposes that Boeing fails to build any real step-changes in the B7E7 which - unlike the engines - cannot simply be transplanted into the derivative technology A350. My guess is they will. Boeing's been through a trough, it's lost it's way for the last few years, and Airbus has done a lot right. But all things go in cycles, and don't underestimate Boeing; it's a powerhouse of technology, and the B7E7 is everything to Boeing Commercial Airplanes. My guess is that they'll succeed in placing the 7E7 beyond the reach of the A350 in terms of overall economics, but that Airbus will then exploit the massively lower non-recurring cost of the A350 programme to compete with the B7E7 on price.