It is illegal to operate 915Mhz equipment in Europe, which is why there are separate stations for Europe (that use 868Mhz IIRC). Will the police come knocking at your door? Probably not, but I'd be more concerned with an errant HARM missile blowing up my home thinking it was locked onto a hostile missile launcher or something.
Why not just buy a wired VP2, and not have to worry about any of this?????