Taking photos or videos of people in UK

Question

It is generally understood that taking photos/videos of people in a public place in UK is not unlawful unless it is done in a place where they can expect privacy, or unless the images are indecent (source). However, there are some quirks to this definition that cause confusion for many people, and I would like to clarify how this rule applies in the UK in a few particular situations:

1. A driver in a car or motorcycle breaks traffic rules, causing danger to other people, and also shouts and verbally assaults passers-by. Is it lawful to take videos of the driver and send it to the police? Or can his car be considered a 'private place' where nobody is allowed to take photos/videos?
2. I notice a suspiciously-looking person roaming up and down my street looking at people's cars. Am I allowed to take a picture of him through the window of my house, and send it to the police?
3. Same situation as above, but I want to share his picture in my area's local Facebook group and ask my neighbors to stay alert and look out for him. Would posting a picture of someone in a public social media group be considered a violation of their privacy?
4. If my child takes part in a school play that I attend, am I allowed to take photos/videos if I know other people's children would end up being in my pictures as well? Is the school building considered a 'private place' where no photos/videos are allowed without explicit consent? Does it make any difference if I keep these pictures to myself vs. if I post them on social media?
5. I have a camera above the entrance to my house that records everyone who comes through the front garden to ring my doorbell. Technically, my garden is a private place where 'people can expect privacy'. But this is my private place, not my guests' private place. Am I allowed to record videos of my guests in my private place without their consent?
6. I see a stranger urinating in my private garden. If I take a picture of him to report the incident to the police, will the picture be considered 'indecent' and therefore unlawful?