Earlier quoted context omitted.
Proponents of creationism do use science, although it is selective science. I think it is important part of critical thinking to analyze a theory in respect to whether it takes into account all evidence or selective evidence. As far as falsifiable criteria, I think string theory would also have a problem under those restrictions.
I've not seen anyone treat string theory as "this is true" though. At best it's "this is a cool idea and it might maybe possibly explain some stuff if anybody can ever figure it out."
I think the problem with creationism is that even though there may be some select science used as part of the theory, it quickly tends to then be used to state that because "this is true" (assumed but unproven truth) therefore this religious doctrine must also be true. I think that is somewhat implied even if not stated and that becomes an issue.
Otherwise, there really isn't much of a distinction between creationism and theories that the entire universe is a sophisticated computer simulation. They are both forms of intelligent design.