Points 4 and 5 are absolutely ridiculous. Especially 4. I hope an ambulance never has to take a detour or deal with a blockade for their sake. It's just absolutely naive to think you can create a blockade and not have an impact on response time. It's shockingly stupid.
Protesting is respectable. However, people and public services have just as much if not more of a right to function than your protest. If you blockade traffic for hours that ambulance is inevitably going to get delayed going to the person in need.
It's common sense and disrespectful to everyone else in society. Even those who are inclined to agree with the protesters.
Although I agree with nearly everything you say it has to be said that..
In most cities, in most civilized countries the police work with the city when a protest happens. They look over the plans and talk to the group organising it to hash out what they are looking for and where they want to be.
They do this for the very reason to make sure a) its peaceful, b) controlled and c) they can reroute traffic which includes emergency services.
It would be the spontaneous protest or those that dont seek the right permission that would be the most disruptive and cause the cops and emergency services the most headaches, but even then the cops would relay the message.
Most US cities have direct alternative routes too so I wouldn't see this as even being a big headache for them. I am guessing the UK has minor roads for them to take detours. Unless of course there is someone hurt the other side of the protest.
It would be the sort of protests like we saw in Hong kong which would ultimately be the type that causes the biggest headaches given the sheer numbers and thus most alternative routes would be blocked too.
That said for those that seek permission and permits I am fine them causing disruption within reason.
Again though I do agree with the sentiment you are making though