I recently lost my C: drive and I didn't have my Joystick Curves profile backed up. When I reinstalled Joystick Curves I could not get it to use my joystick and throttle at the same time. It would recognize either one, but not together. So I had to go through the frustration of running the TARGET software. As far as the USB key number goes I think this is because it is universal and not slaved to any particular language. One of the nice things is that you've got a lot more "F" keys than the average keyboard so you've now got unused keys because anything above F12 won't be used. It works out well for me because I 10 keyless keyboard without the number pad and with the TARGET software I gain those back so to speak. I'm out of town and I'm doing this largely from memory so bear with me and maybe I can get you headed in the right direction.
I assume that you followed the instructions found in the How to load the Target profile for Elite Dagnerous.pdf and are familiar with that. One quick tip before I begin, I had no issues stopping, then editing the FCS Hotas Elite Dangerous.fcf profile and then running the profile again while in game as long as I wasn't trying to actively fly the ship. This will be handy once you start working with the curves as it helps you tweak them in to precisely what you want. When you run the profile again, make sure it says “main returned 0” before attempting to fly in Elite.
I wouldn't attempt to do anything with the curves until I got the key binds where you want them. The good news is that the curves are easy to do and once you get the hang of it the curves you can make in TARGET are very versatile and you can get better results with them than you can Joystick Curves.
I would start by removing all of the key binds in the ED configuration screen that you don't use or are not what you want them to be. Now that that is done start binding the buttons the way you want them. If you noticed, the ED configure file doesn't see the USB number, it sees the letter that it represents. You don't have to go back and change anything in the TARGET software. When you hit a duplicate key bind it will tell you what key bind is duplicated so just go and unbind that key and either leave it empty or bind the desired button in its place. All of the buttons that are used will be a unique key from the TARGET keyboard so literally all you have to do is just re-bind as usual. For instance, if you want to use the top hat switch on the throttle for the SLF functions instead of the wingman functions all you need to do is unbind the current functions go to the section you want and start binding.
If you run across a button that isn’t bound leave that until you have all of the rest of the buttons doing what you want them to do and then go into the TARGET software, stop the profile, edit the profile, go to the Event screen and add a new EVENT. Follow the guide in the user manual located in chapter 7. You will see all of the events and I don't usually remove any of these but I might rename them to the new use of a button if you want to.
Now that you have the buttons bound the way you want them to and it’s time to set a curve. Once you’ve done one you will understand how to do all of them. Go to the manual and look for “Configure axes response” and it will explain what you need to know. Play around with it and you will soon start to understand how it works. Do on axis only until you get the hang of it and then add in the rest until you get them where you want them. If you have any questions I’ll try to help but I’m on a job out here and it may take a while to respond.