According to the game's description found on the Steam marketplace, IL-2 Sturmovik 1946 only works on: Windows® XP/2000. Since it's a 32-bit application, you may have some trouble running it on Windows 10, but you can still work around that: first try to right-click the application's executable file, then go to Properties and in the Compatibility tab, check the Run this program in compatibility mode for box, then select one of the supported versions and press Apply. In case that didn't work, you can always create a virtual machine and install an older Windows version on it or use an emulator like DOSBox.
For your second question, the answer is yes, the game can be controlled through a joystick and it was actually designed to be played liked that, so it will be a lot more fun than using a keyboard.
