Out in the provinces, most ramps have to be manually deployed by the driver. It's different in London, it's mechanically deployed from the comfort of the cab.
There's also more room on provincial buses, as they don't have that second door, which always helps.
As for the use of PA, in conjunction with turning the engine off, it is fairly common when drinking or smoking happens on the bus. The problem is attitude: smoking or drinking on the bus is (rightly) seen as anti-social behaviour, but refusing to move for a wheelchair user is not. Most drivers, IME, don't even bother asking, they just shrug in a way they wouldn't if someone was smoking on the top deck. Ironically, most buggy users would actually move if they were aware they needed to.
I can't remember the last time I saw anybody illegally smoking on a bus, it can hardly be compared to somebody being unable to fold a buggy.