Some rich remain rooted to where it all began. In racing, they even build hotels. JP McManus – despite his status as a tax exile since the 1990s – is revered in Limerick and specifically Adare, where the five-star Adare Manor has to be enjoyed to be believed. A friend who stayed there recently was momentarily lost in one of its corridors and bewildered when help arrived within seconds. McManus, who turns 74 in March, remains an enigma: he hardly ever grants interviews. Neither does John Magnier, a tax resident in Switzerland, who greets his 78th year in just over…