Unfortunately, “they’re all like that sir.” The T-Flight Hotas one is a get-you-going controller, and built down to a price - although it undoubtedly makes flying much easier and more realistic compared to using the keyboard. The plastic ball and socket gimbal and the electrical sensors used in this and most other TM devices is the root cause of the problem, in that they just aren’t very precise. The same thing applies to most Logitech / Saitek and Turtle Beach devices so I’d suggest not replacing it with an X52, X56, T16000m, Airbus Captain, Velocity One or Warthog as there will all have the same inherent problems to a greater or lesser degree.
The Thrustmaster software - such as it is - for the T-Flight Hotas does not as far as I am aware allow you to calibrate the device, so this is where I would start. This earlier discussion covers the issue, and in post #10 there is an explanation of how to calibrate it using the native Windows controller tool:
If that doesn’t resolve the issue, the only options left while retaining the TM Hotas itself is to keep on adjusting the Response Curves and the Reactivity within MSFS. I would caution against setting an ever-increasing deadzone, as this effectively gives you less and less joystick travel to work with and therefore makes the switch from no movement to full movement even more extreme. I’d set it minimally, so that there is no input detected when your hands are off the stick and leave it at that.
It is possible to significantly reduce the issues you describe with the Hotas-1 through the MSFS settings, and with more time and practice you will improve - it takes subtle and sparing input to fly smoothly.
In the longer term, changing the joystick to something better would transform your experience. The VKB Gladiator NXT Evo is hands down the absolute best entry-level joystick, with a gimbal design and build quality that far outstrip the mass market devices mentioned above. If you can find a decent used one, even better - for a plastic joystick they are built like comparative tanks. If buying new, they have local distributors in the EU, UK and US. Used ones don’t come up all that often because people tend to keep them for good reason, but keep an eye on local marketplaces and auction sites.
Virpil Controls also make excellent joysticks in a similar vein to VKB and now offer the CDT Aeromax as a starting point, but until recently they didn’t offer anything in the same low-ish price bracket as the Gladiator. Note that the Gladiator comes with a basic throttle control built into the base (i.e. it can be considered as a hotas), whereas with the Virpil you have to buy and add the dedicated throttle module yourself, although it’s very inexpensive.
Both VKB and Virpil offer excellent and powerful software for setup and calibration of their products, and have active and very helpful forums and Discord channels if you need guidance.
Plenty of flight sim users will point you towards WinCtrl (previously WinWing) joysticks such as the Ursa Minor which is attractive and inexpensive, but I’d suggest caution and some reading around first. The gimbal used in the UM appears to be a very close copy of the one used in the VKB Gladiator, but the implementation and use in practice has not been seamless and there are a lot of reported problems with the devices and their customer service.
Good luck!