I live in uk nearly 30 years, I live in London (zone 6,) and I have family of 4 in 5 bedroom house. Here is my spend excluding mortgage every month. Electricity and gas £195, council tax £203, phone £45, water £38, TV license £13, house insurance £280 ( per year), car insurance £550 (per year), food £550, mobile £40, I think depend on house you rent 3 bedroom house around £1900-£2300 ( zone 6). Petrol £100 All other expenses depend on your lifestyle
You haven't touched the topic about grammar school. I believe some people may not be aware of this education system. I guess it might be worth mentioning that in your channel
I live in Colchester. I would say it's Level 3. But you also can find many 300-400k houses, or houses that cost over 800k (eg., Lexden Road) in this area. Quite a mix actually.