British: What Brexit legal issues concern you?

As the UK leaves the EU many legal problems may arise concerning employment, pensions, land sales, taxes such as the wealth tax, access to health care, capital gains, visas and work permits. It will be a legal landfield for many British citizens. While larger corporations will view regulatory and trade issues as paramount, what about individual British expats living in Spain and elsewhere in Europe. I am studying these issues as a retired US lawyer-journalist and would appreciate feedback from British expats, others.