Nice report and photos! I'm a Singaporean so it's nice to see reports about your own country. I like the photo of the MBS light show. Tbh, i'm not even sure of the exact location you took that photo from
You mentioned you went in October and had to pay the departure taxes again. I was in Indonesia in Oct and I flew on GA too on a few flights and I had to pay the departure taxes separately too, because in my case, the taxes weren't included in the ticket price when I bought my tickets. Perhaps they assumed that not many people bought the GA tickets in advance hence most if not all have to pay the departure tax separately?