hopefully yes, but a fuse/mcb won't trip on the current/voltage that
gives a fatal shock - you need an RCD - even then that takes 0.4s - or
40 half cycles each reaching a peak 340volts.

No it doesn't. That may be the spec, but the RCD will probably trip at the
next zero crossing point (or the next one in a particular direction,
anyway).

The spec for a 30mA RCD was designed to ensure adequete shock protection
without leading to unnecessarily complex design or excessive nuisance
tripping.

& minimising exposed metal surfaces in a kitchen.

Indeed. The IEE recommend even in bathrooms that any metal surfaces should
be isolated if possible, rather than earthed. It is only if they will be
earthed anyway (perhaps at a different potential to other parts) that
supplementary bonding is required.

Christian.