If you're flying CX then you shouldn't have to worry about the pilots mishandling the situation. I'm not going to sugar coat the situation because pilots have mishandle poor weather situation before either by mistake or by cowboy attitude. This is simply a chance you're taking every time you decide to fly. It is out of your control much like how temperature and air circulation works. If you are in the Seattle area, it appears there is a clinic to address the fear of flying, "Fear of Flying Clinic Seattle". They may be better at easing your concern than me. As I said previously, I got less nervous when I started flight training but I wasn't scared to start with. It's not just the sensation of flying a small plane in choppy and hot conditions but also attending ground school to learn about basic theory of aerodynamics and weather conditions that helped.

Here are the reasons why I don't think turbulence will end up in the worst case:
1. Airplane designs have come a long way, it takes a lot to break things.
2. Pilots at the safer airlines generally have better training, they know the limits of the airplane, the limits are well published by manufacturers, for example, the max speed the plane should fly at during gusty conditions (Va & Vb).
3. Those squeaking sound during turbulence most likely come from the interior fittings. Think about how your car squeaks when it goes over bumps. Is your engine going to drop out from under your car? No. It is the door panels and seats that are making that squeaking sound as they rub against each other and the metal structure.
4. Airliners usually have at least 1 backup to all critical system.
5. The sensation of having your seat drop out of you / the plane fell like 3000 ft a second comes from the spike in vertical acceleration. You are not glue to the seat but the seat is bolted to the plane. So when the plane drops a bit, your body isn't for a brief moment which gives you the sensation of falling like 3000 ft in a second.

This article seem interesting, Point #4 , pick a flight earlier in the day during summer time to avoid thermal related turbulence. If I recall correctly, the new CX SEA->HKG flight leaves around 1AM and arrives around 5AM in HKG. So in theory, it should be a bit calmer than the afternoon flights we get in Vancouver.

https://www.usatoday.com/story/trave...ence/12301043/