This is true that it might feel disconnected, when the input is faster than it's needed to be, since there is no way to force a speed limit on a mouse.

I've experienced similar issues. When I try to move the supplies it usually happens on like 3-5th attempt. I think it depends on the ping. Similarly, sometimes I need to press the respawn button up to 5 times to actually respawn. I usually have around 80 ping on official servers in Europe and 150 for American servers. Maybe the devs could try it with fake ping or actual ping on American servers

It might more of a taste question, so allowing for players to choose sensitivity for helicopters would be the solution, I think

I think the controls are fine. The sensitivity allows for very precise control, and in the rare cases when you need to turn at max speed for a long period of time or in the extreme scenarios you can use WASD. But there is a top speed limit for the mouse. If you move it too fast, then it won't register. So I'm moving my mouse very slowly and I have more than enough mouse pad space, even though it's not that big. It might be hard to get used to it, since when you turn so slowly you might want to move your mouse faster, but it just makes it worse. So, "impossible" is a great overstatement.

I didn't know that. Anyways, what's their purpose in the game? You can't use them in any way (you have to lower them to use), so that's confusing.