About Kilrathi Saga...
I recently was able to get Kilrathi Saga, let me share some of the things I've done.
First, because you use XP, go to where the game executable files are (the '.exe's). They should be in a folder in your programs directory called Kilrathi Saga and then inside sub-folders for each game called "wc1","wc2", and "wc3". Go inside the folder for Wing Commander one and then right click on the file called WC1.exe and head to propertise. Tab to "Compatability" and check the compatability mode option on and select Windows 95.
For me this made each of the games a bit more reliable and also fixed some keyboard oddities. But unfortunately, because of the way I think Windows polls the keyboard, you really won't be able to fly with the keyboard like you did in the DOS days. It just isn't responsive enough. This is even in one of the inserts and Origin basically said you really can't do anything about it and I think this is still true. Try flying with the mouse - the 'tab' key for afterburner should work just fine after you turned on compatability mode and 'enter' works fine more the missiles too. You can do both afterburner and fire missiles with the mouse, too, but I don't usually.
Also, despite what I've read and thought to be true, you can adjust the inflight game speed (at least in Wing Commander II, I haven't gotten to Wing Commander I yet). When you are inflight hit Alt-N or Alt-M to adjust the game's speed.
Hope this helps you.