I am Chinese from the mainland and had worked in HK for several years. Maybe I can supply some information abouy HK.
About the air travel, I would recommondate 'Cathy'. This is a HK based company. Its service if of good quality and its lines cover all the major cities in the US, including LA, SF, NY.... and in the Southeast Asia of course.
For the local interesting places, Victoria Peak/太平山 in HK island, where the view is good especially at night, and the Maclehose trail (there are ten stages, enjoy them), are suggested. Almost every local people could speak English very well. So just ask for further information.
For the escorts, my experience may not be helpful to you but I just let you know. There are many money boys from mainland China. Usually they stay in HK for one or two weeks and go back to the mainland or go to Singapore. But mostly they can't speak English at all. Some of them told me that they can use some translation apps to communicate. You can use Gayhk.com to look for the guys you like. Many ads use photoshpped pics if not totally fake ones. And to most people from mainland including the boys and myself, Wechat is more popular than Whatsapp. However, I have no idea about local spa and the international travelling escorts in HK.
About Macau, it is full of casinos. If you don't like them, I think you just need to stay there for one day at most, because it is very small.