Hi,
The common area of the roof structure is owned in joint by the members of the body corp of there strata scheme. They have a say in joint as to what is acceptable. No one owner of the scheme can install any item on the buidling structure without the consent of the majority & close neighbours & local council regs for hot water, solar panels, saterllite dish.
You are correct in question 3.
I hope this may of been some assistance to you.
I voluntary assist in the admin of a strata scheme and have lived in strata schemes for approximately 20 years.
Yours Sincerely,
Digby