Walking on the streets of Hong Kong is one heck of an experience. You can bump into 30 people and every one of them just keeps walking as if nothing happens. There's just way too many people in Hong Kong, so I guess they're used to it. In Toronto, you can walk down the busiest street on a weekend and take up the whole sidewalk. LOL
Ga jai, for me is not a negative term. But it really depends on how the person’s attitude at that moment. New generation don’t use this term anymore but some elderly still do. I would say half half. Half of them treat it negative and half of them just use this term neutrally. :)