Veyron254
The 2500 nm range quoted is based on optimum conditions, still air, ISA temps, 30 minute hold at 1,500 MSL overhead the 100nm distant alternate, that's NBAA range. You seem to put a lot of stock in RVSM, if you cruise above 410, RVSM gets you nothing and you will NOT beat the manufacturers range projections. Further, the range is predicated on no ATC delays in the climb, not being kept at intermediate altitudes, etc. Much more likely, you cannot operationally match them. RVSM capability will do nothing to increase that 2500nm quoted
Your "dry" footprint needs to be calculated based on loss of pressurization OR loss of engine, whichever is more restrictive. The loss of pressurization will, in nearly all cases, be the more restrictive. Your FMS can only calculate ETP on current or entered winds, so cannot do the calculation for a divert at FL100 or whatever is the engine-out ceiling.
While your analysis of regulations is quite correct, your lack of understanding of good operational practices and basic navigation is lacking. The regs in this instance, give you the rope to hang yourself. I have listened to the pleas of someone who has erred in those practices and calculations, not good. Please do some research and training on long-range navigation, airplane capability and international procedures before striking out "feet wet", unless luck is your chosen methods.