The seller thinks the value is net negative to them. The buyer thinks it still has a potential positive value. Both would agree to just hand it over.

Unfortunately, UK law does not allow that. Consideration must go both ways. The simplest way is to sell for the minimum reasonable amount. $1 is traditional in the US. In the UK it is £1. The other commenters link has a good writeup on the practice.

They broke from "everything is a pound" years ago. They also still do a really bad job making it clear what is no longer a pound.

You're likely picking up on her autism. Most aspies put on a (mental) mask to interact with others. For most it's intended to be inoffensive and keep you in the background. Greta's is focused on her goal. She would likely prefer you hated her, but knew about her causes, than be likeable, but forgettable.

As for harmless, that's part of the image. She's as harmless as a friendly bull. It will happily get scratches behind the ears, but still walk straight through the wooden fence to let the cows roam free.

You've got some catching up to do then.

Pink is countries the UK has invaded. Purple is everyone else.