: Eric Clapton is unusual in that "God" wasn't used as a nickname (roadies didn't greet him in the studio with "Alright God, 'ere's your guitar") but it was an honorific from the famously well-known London graffito, "Eric Clapton is God".   
 : Mercury I wouldn't know about, except possibly "Squaddie's favourite". As always on Wikipedia though (see WP:OSE), the notability or not of one topic is simply irrelevant to another - we treat each individually. If you can source good references for either (and for a "fluffy" topic like this, they'd better be good) then by all means add them.    

 == "Hardest working (wo)man|band in showbiz" == 
 Seems like an omission, but who warrants it the most?