Yes, string theory presently is closer to science fiction than to science. Also, it is based on such an obscure mathematics that we laymen must trust other flawed human beings, even if physicists, to be right.
I see one common feature though between string theory and Hindu metaphysics, that is the fact that the cosmos are fundamentally a vibration, the strings are configurations of vibrating energy, hence the basic makeup of the universe would be vibrations, as Yogananda writes.
The interesting point i see here is that most scientists have pooh-poohed the claims of yogis and psychics. Now we can just as easily disclaim their discoveries on the basis that they cannot verify them in experimentation which has been their big disclaimer about spiritual experiences.