You have answered your own question. ALL of the conditions must be satisfied & that means condition (d) must also be satisfied, i.e. the costs of the flight MUST be shared. So if you are cost sharing, the maximum number of people on the flight, including the crew, is 6. If you are not cost sharing, the entire (7A) section is not relevant & therefore there is no restriction on the maximum number of people on the flight.
Does this then mean that a private aircraft owner who takes a friend for a scenic and wears the cost him/herself without asking for remuneration from the passenger, that it's no longer classified as a private flight because 7A is invalid? If it's not PVT, what is it?