Just the address of your first place of stay would be ok.
You don’t need a return or onward ticket for a Non O visa. A non O is not multiple entry. You’d need a re-entry permit if you wish to leave before the 90 days to keep your current stamp date valid.
Not sure where you read information on the Non OA / OX but they are multiple entry visas and don’t require re-entry permits for the duration of the visa.