Hi grolsen,
I am not with Laminar Research; just a flight simmer from downunder.
You have raised quite a number of issues in your question.
I also have the XP10 dvd version with the dongle and works fine on my new rebuild.
1. X-plane version 10 is a totally different package to x-plane version 11. If you want to run XP11 then you will have to purchase the product from Laminar Research.
A disc version is also available through Laminar or their agents being Aerosoft. There is no substitute "dongle" available for disc 1 in XP11 as there is for XP10. The XP10 dongle will not work with XP11. Like XP10 there is no product key with the XP11 disc version. XP11 is far easier to use than XP11.
2. Have a look at the following link found at https://www.x-plane.com/product/x-plane-10-home-use-usb-key/ to see what the XP10 dongle looks like.
3. From my reading of your question you also have a digital download version of XP10. If you can salvage any purchase details contact Laminar Research by email at either [email protected] or [email protected] to obtain a replacement product key.
4. Purchase the hardware that you can afford. Style and pricing varies quite considerably. Have a look at the X-plane.org site. This site is dedicated to X-Plane and is not associated with Laminar Research (X-plane.com). Whatever you purchase make sure you install the hardware through X-Plane. Not through your operating system and "dump in the bin" any software that is supplied with the hardware. Particularly software from Logitech. Follow the concept given in the following link found at https://www.youtube.com/watch?v=hU_TuALAlJk. Do this for each hardware item.
Good luck
Glenn