This one’s easy. No, no, no, no, no (yes, occasionally) and no.
By and large, venues, festival organisers and promoters who insist that musicians bring a certain number of ticket-buying punters to their gigs should pretty much have their licences revoked in my book.
The argument goes something like this: playing at our venue / performing as part of our festival / taking part in our Battle of the Bands competition will be good for your profile – and you may even get a record deal out of it. Or something.
Promoters know it’s shonky, which is why they often go to some lengths to make it something of a secret that this even goes on. One recent local example is the rather shambolic PR disaster that is the Surface Unsigned festival.