OK, so we are intending to move to Spain. We fully expect to live there for the next few years at least, but you never know. When we leave the UK, MrsC will be unemployed, though with some self-employment, I will be self-employed, earning income from a third party Eurozone country.
Until we are at least reasonably sure we aren't going to scurry back in a few weeks with our tails in the "between the legs" position, I don't want to go around burning bridges with UK authorities.
So, initially, we will use EHIC cards if we need healthcare and I will continue to pay UK tax and NI.
However, I fully appreciate the requirement (and intend to fulfil it) to join the Spanish system once our position is clearer. I'm told many ex-pats take out private health cover as it is less bureaucratic and in some cases less costly than the (supposedly excellent) Spanish public healthcare system. As I will be self-employed (again, paid through French clients), I'll have to register as a business, but at what point?
Who would be the best "specialist" in the UK system to ask for advice?