AOG
Your suggestions aren't laws. They would be security protocols.
The idea of chipping knives is unworkable for a variety of reasons.
1. People buying a canteen of cutlery would not be able to take the bus or tube home.
2. Kitting out every bus, tram, underground train, overground train and riverboat in the UK would be prohibitively expensive. Who would pay for this? Is the risk justified?
3. Knifes are made of steel. As a material it doesn't not transmit radio wave well.
4. The idea of preventing people from getting onto public transport with weapons does not solve the issue of people carrying weapons.
5. The cost of all knives would go up. The technology to embed chips into knives would be passed on to the consumer. That means that all restaurants and catering companies would pass this increased cost onto their clients.
The laws we have at the moment are adequate, because we have to balance what is sensible with the danger posed.
I don't think your proposed ideas are at all workable.
What I think would be a more practical idea is an increase in police presence on public transport. Of course, this would mean a massive increase in funding, but I think that the majority of people would support extra officers on the tube, buses etc, rather than having to pay and extra £20 for a Sabatier knife at John Lewis.