To answer part of your question, i think it's not quite possible
to integrate other weapons into the F-15E, provided the one we are
being offered is around the same weapons configuration and
technology as the USAF's. In my opinion, the F-15E is the most
battle-proven among the three but in the competition, other aspects
are considered as well, I'm sure somewhere in the thread they
explain it but for me, its the Rafale which is the most
technologically advanced, though some may disagree...
p.s. for quite a while, i was rooting for the F-15E...