1. NHS, and the tinker GPs + their disgusting consulting rooms with no hygiene
Get a copy of the Highway Code and take some driving lessons.
5. stupid, non-metric measures
That make sense to us.
7. calling me Polish, just because I am White and non-English
In the UK, there are two types of people. British people and foreigners, unless you work in a callcentre and have a foreign accent of some sort, in which case you're Indian.
8. the English never wash their hands in the toilet
If you mean literally, then I should hope not.
9. plus other stupid things we don't have to mention (two taps for boiling hot + arctic cold water etc.)
I think your lagging needs checking.
Enjoy your stay :-)