I have a bog standard B&Q 250 Watt chrome plated electric towel rail with its own integral live, neutral and earth cables enclose and hidden away safely via rubber seal and hex screw tight fitting to main frame as per manufacturer's instructions.
It has an earth connection, therefore the body is earthed therefore you need to read up on supplementary equipotential bonding.
http://www.google.co.uk/search?q="supplementary+equipotential+bonding"+(17th+OR+2008)+(7671+OR+"wiring+regulations")
I do not want a flex plate in the bathroom
So you're just going to have the flex going through a hole in the wall? That's nasty.
it looks neater than a large flex plate with metal screws fitted to hold it in position.
If you say so.
A hole in a tile will be sharp - how will you protect the flex from damage?
How on earth can the flex be damaged; no one can reach it without difficulty and the flex will never move. the hole and flex make a very smart and safe and attractive finish; one could also say that by fitting a flex outlet plate inside the bathroom hidden away from touch that the plastic hoe in the plate could cut the cable; this is not so.
Finally the circuit is connected to the consumer box 30 Ma RCDs the SFCU having a 3 amp fuse fitted.
Why a switched one?
Because I favour having a switch to switch on or off.
Why do you want a fuse at all? safety precaution.
So, such a simple job it should be; what are your thoughts on the above.
As I said, you need to investigate bonding.
Also, you've not answered the question about the lighting circuit being RCD protected. Yes it is.
http://www.google.co.uk/search?q=rcd+bathrooms+(17th+OR+2008)+(7671+OR+"wiring+regulations")
PS - apologies for the fact that this poxy forum software prevents search URLs from being proper links - you'll have to copy & paste...