Fractional reserve is definitely possible as soon as bitcoin credit and mainstream-like institutions appear. It is necessarily a good thing, but without the federal reserve and FDIC, there is no socialization of risk and moral hazard.
Yes I agree FRB is possible. But I don't agree it is a good thing. It is no because it is a fraud. And as it goes with any fraud it is possible to happen.
However my point is that because of Bitcoin nature one can not sustain such fraud in a long term, i.e. the FRB will not work. All attempts to do FRB will lead to a crash of such institution.