Does "fight their would-be liberators to the death" mean...?

No, it's the other way. They have been so brainwashed that they think their would-be liberators are actually the enemy, so they would actually fight against liberation and liberators.

what you must believe to be a good Muslim, to have military and
economic power, and to not pose an unconscionable threat to the
civil societies of others? I believe that the answer to this question is
no. If a stable peace is ever to be achieved between Islam and the
West, Islam must undergo a radical transformation. This transfor-
mation, to be palatable to Muslims, must also appear to come from
Muslims themselves. It does not seem much of an exaggeration to
say that the fate of civilization lies largely in the hands of "moder-
ate" Muslims. Unless Muslims can reshape their religion into an
ideology that is basically benign-or outgrow it altogether-it is
difficult to see how Islam and the West can avoid falling into a con-
tinual state of war, and on innumerable fronts. Nuclear, biological,
and chemical weapons cannot be uninvented. As Martin Rees points
out, there is no reason to expect that we will be any more successful
at stopping their proliferation, in small quantities, than we have
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been with respect to illegal drugs. If this is true, weapons of mass
destruction will soon be available to anyone who wants them.

...(1) Does "or outgrow it altogether" mean "or completely surpass religion itself"?
(2) Does "weapons cannot be uninvented" mean "you can[not] invent a method to make the invention of weapons invalid and disappear (people would even think there have never been such things as weapons)"?

"would-be" can be either neutral, positive or negative, depending on the context. It's not self-titled. A better synonym would be "potential."