Thank you James.
Having read all 3 opinions and rechecked the quickbooks section labels, I'm inclined to believe that the employment start date should really be that when the director actually became an employee (so in the example I gave, that would be July 1). This is mainly because that section is asking when the employment started (not directorship), and generated a new unique payroll ID for that matter.
As for the tax information section, it asks if the person is a director and his appointment date. So judging by the wording, I'd say this should be when the company was incorporated. Although, I still fail to see what relevance that would have to the payroll if the person was not an employee up until now.
Any further inputs are always welcome.
I think this is the 4th time I edit the appointment date, and I hope it's not being resubmitted every time. It's not an RTI submission yet, just editing employee details.