Turbulence, Jet Wash, & Refueling.
I agree to point. When refueling you do encounter some difficulties. Especially if the tanker is flying below 400km per hour. The Su-33 can become difficult to control at slow speeds especially when trying to connect to the drougue. I find that when setting up a tanker flight I make sure that the altitude is locked and that the tanker is flying at a speed anywhere above 500kph. Try that setting and I am sure you will notice the difference in the flight characteristics of your plane. Also try a refuelling flight on HL. The host is the only person who can see the drougues. As a client you have to fly using the cues on the HUD until you connect, then the drougues become visible. It's great practice and helps fine tune your stick control... Best of luck with that.