Somebody please explain to me:
If salaries in Europe are so poor why are you guys not doing commuting jobs in China?
I understand the medical issues but if you are a captain with reasonable experience under 40, the medical really should not be a problem for the majority. Simulator checking can be a problem as the Chinese have their own ideas but you can familiarize yourself with that, maybe have a go two or 3 times.
If you really need to be at home then negotiate with the Chinese agencies, you could probably work 1 week a month for 5000 euro's.
It is all certified tax paid at a rate of 40%. Leaves roughly nothing to pay in the UK.