If you really could talk to the dead wouldn't there be something more valuable, both to yourself and society, to do than trawl around theatres telling vulnerable grieving people that their Dad Dave, no hang on, Derrick, oh, no, Desmond, no, no, Dilbert, yes Dilbert, is fine and happy in the spirit world and he likes what you've done to your hair?
No scientific test has ever proved any of this what-so-ever, not once.
However....
"My view is that all psychics, mediums etc should have to prove they are genuinely talking to the dead/feeling auras or whatever the hell their claim is, or, be charged with fraud."
You can't "prove" religion either, so there's got to be some basis for allowing unprovable things. Personally I'd rather Psychic Sally label her shows as "lying manipulation of the vulnerable and grieving to fill my pockets" rather than "entertainment" but I'm sure it's horses for courses.