Regarding visas, Monahos answered very accurately.

I had a nice experience with Emirates, although not in Y, so I don't know. I'd choose DBX over SIN. The markets are very interesting, there very good hotels to stay at, a try at arabic food worth the while, shopping is excellent at almost duty free prices, the modern architecture is very interesting. Some of the nicest buildings ever seen. It is just different and therefore worthwile.