If you moved back to the UK to resume your residency then I agree totally that you should be entitled to receive FREE medical treatment as soon as you arrive. But at no point have you stated that would be the case, in fact everythng you say suggests the opposite. Which means...
"If you move away from the UK permanently, you will no longer be entitled to medical treatment under normal NHS rules."
Not sure how you can claim my question about what it takes to get free healthcare for life was irrelevant. With immigration/emmigration to/from the UK happening more and more, and a greater number of people obtaining British citizenship/passports who weren't born here it is likely to be a bigger issue in the future.
I notice you choose to ignore my question about whether I ought to falsely claim benefits. By your admission you are now considering claiming something from the UK government you are not entitled to, which shows the sort of person you are.