Hello,
Simconnect is one thing, serial comm with Arduino other comm channel. Simply said, you need collect data from sim via API and then send via serial (or USB as serial port) or ETH port to Arduino. You need create simple bridge inside your application.
HID, yes, you can use this feature like simple general defined HID device. I think you need define Arduino functionality with driver type, if I good remember. I did my MS sim with Arduino quite long time ago. Try look at Arduino main web for functionality.