Everyone seems to enjoy blinding me, didn't see any issue with returning the complement.
The lights seem to be Z beam. So basically if I'm a bit high I can use the load adjuster to keep others happy. I also readjusted the main beam, one was pointing at the sky and the other 10ft in front of the car (don't ask me how that passed the MOT just before I bought it...). Now if I put the main beam up everyone knows about it and I can see the road.
You can keep a car indefinitely on the roads in the EU if your registered address is the UK. Whilst we may have a home in France, I work all over the EU and occasionally in the UK, so I keep the car registered there. If you emigrate with no address in the UK you have 6 months to register.