You said "However the lift fan and engine are capable of another 10% growth in VLBB." That seems eminently clear, but I accept that it's not what you were trying to say. However, it contradicts what P&W said when they were trying to scupper the GE engine, which is that the lift system would require major redesign to deliver more VL thrust.
I don't understand your point about the F-15SE. There is clearly some risk involved in any innovation but it is a quite small step beyond the fully funded F-15SA.
As for other countries: They bought into the JSF on cost, schedule and industrial participation projections that are rather different from what they see today. They are under enormous pressure externally to remain loyal (see Wikileaks) and, internally, deal with AFs that have long relationships with the USAF and are very reluctant to switch suppliers. It's thus very easy to do nothing and hope it will all turn out right in the end, since at least the partners have not been stuck with the development overruns.
Engines - Would not disagree with any of that. However, the long life of most modern fighters in production and service has been achieved through adaptability to new technology and new missions, and this has been accompanied by increases in empty weight, useful load and thrust. An F-16 Block 60's empty weight is a lot greater than that of a Block 10.