Although it wasn't made public at the time, Bert received more votes than any other player in the inaugural Hall Of Fame vote. If my memory is correct he was a good few hundred (no one received more than 10,000 votes) more than Colin Bell and then Joe Corrigan!
As for best keeper... it's a generational thing. I prefer to say Swift was the greatest English 'keeper and Bert the best overseas, but which one is best overall who knows? Either way Hart shows signs that he will eclipse them both.
Interestingly, MANC magazine claimed Corrigan was greatest City 'keeper of all time.
Greatest player - in fifties (after Swift & during Bert's time) the argument was between Billy Meredith and Peter Doherty.
In the 70s most had forgot about Meredith but Doherty remained, only to be challenged by Bell in views by the late 70s.
For some fans City's greatest player will be one of the current stars. The game's changed so much that it's probably best to claim 'greatest of that generation'. We'll never prove whether Meredith, Swift, Doherty, Trautmann, Bell or... whoever is all time best. Let's be happy to say we've got a rich history of great players.