I agree that H2 can be handled safely. It is handled in Huge quantities in oil refineries right now and is also transported via pipeline.
However, this is in an industrial setting specifically designed for the hazardous area class that arises.
I think the point of the previous post(s) is that this is a far cry from Joe average playing with the gas in his garage.
Also, automotive applications are going to have serious requirements for the fittings and valves do to the constant vibration and collision potential. This is not a rocket engine that needs to perform reliably for several minutes, an automotive application will need to last years with somewhat questionable (i.e., shoddy) maintenance.
As a side note, when I have used H2 in plants I always specify all pipe and fittings to be seal welded.
Finally, the real question is not can all of this be handled (of course it can), but can it be handled economically and in the forseeable future?
As I stated before, I belive that the first automotive applications will probably use on-board reforming so as to (at least initially) avoid the H2 problems all together.