No, you can have switches, it doesn't have to be a pushbutton. You would write the sketch so that the Arduino sends a command to do whatever you want ( toggle lights as an example ) when it changes position.
But before entering the cockpit in DCS you will have to make sure that the switches correspond to where they normally are. Like the landing gear, if you start on the ground then it should be down, in the air up of course.
If not the switches will still work, but backwards.
I hope you can understand all that and I haven't confused you :D
What you are planning to do isn't too difficult, I am not a programmer but I managed it - and if I can do it, anyone can :smilewink: