Well for a start there's been no evidence that the guy in Oxford was ever in threat of being assaulted. You've just assumed he was. He wasn't being protected by the police. He was handcuffed and put in the back of a van after being arrested. That doesn't sound anything like the heroic boys in blue protecting an in danger individual.
They weren't watching a hearse. They were at a proclamation of Charles which he disagreed with, which was hundreds of miles away from where the coffin is.
Yeah, it's not something I expect in the near future. As with other things (reversal of Brexit for one) we're reliant on older generations dying off and the younger ones wanting change. We'll likely be onto William by that point.
There are plenty of good arguments for a Republic ffs. Just because BG didn't list them in that post doesn't mean there aren't any. You choose not to listen to them.