too much negativity? Airbags won't deploy if seatbelts not worn, not only due to design or assembly issues. Just give them some time and see, otherwise our country never progresses..
It's X amount of kilometers or X amount of months - whichever comes first. In your case, the X amount of months has come first. So do the service.
Engine oil breaks down over time regardless of usage. In a humid country like Sri Lanka, the impact of humidity on oil is higher.