Hmm
Try to get your national insurance (NI) contributions refunded when you leave. Get health insurance via BUPA or others, it's of variable usefulness. Are you staying for years? They had a tax-deductible investment program (ISAs in my case) which may be useful for a ten year horizon.
Public school (like in Australia) is variable but can be atrocious. Cost of living was higher in the UK but Aus is catching up. Much much cheaper out of London. Dont be afraid to eat in English restaurants, the quality can be great.
Other things- ice skating in the Strand, long walks in Oxfordshire, rural Scotland is magical, Eurostar, Easyjet, Christmas concerts at Kings College Cambridge chapel..