As long as you are aware of the risks, the best judge is you. There arent any laws around being in a non-sexual relationship where one person is under 18 and the other over. Once you turn 16 its not illegal for someone to have sex with you no matter how old they are.

Is it legal if both are under 16?

In New South Wales, the age of consent is fixed by law at 16 for both heterosexual and homosexual sex. It is important to understand that it is not a crime for children under 16 to have sex! The law criminalises people who have sex with under-16-year-olds.

Is it illegal to have relationship with a minor?

As long as the relationship isnt sexual then its completely legal. Once the minor turns 16 then he/she can legally have sex with the older partner unless there are older than 23 and are above 4 years older than them.

Is dating someone 15 illegal?

In a Nutshell: Sex between an 18 year-old and a 15 year-old is illegal in California, meaning any touching of “private parts” of either, even with consent of both parties (and perhaps even the parents of each teenager) is illegal in California because the age of consent is 18.