"John Orrett" wrote
| 2. Should that read 32A or 16A fuse?

I think the "31A" was a typo for 13A or 16A

| 3. Should "dual pole circuit breaker" be "dual pole isolating
| switch" by any chance?

In some European countries MCBs are double-pole. A DP switch would certainly
be required in the UK, even though / because our MCBs are SP.

| As we are re-tiling and fitting a new shower as well
| as the bathroom suite, we may be able to cable down the
| existing channel from the shower.

If this is an electric shower then you must not use the shower circuit to
supply any other apparatus. Also, you should be aware when running cables
that they must run in permitted zones (up, down, across from visible
accessory) or must be mechanically protected.

Owain