Sevas,
If you just copy all of the template files into the mods\aircrafts folder withouth changing anything, do you see it in main menu, mission editor and in flight?
If you do, then it's a process of elimination to see what file is causing your problem.
I would suggest step by step like this:
Copy templates files to mods\aircrafts - do not rename anything
Export your exterior 3d model and rename that file to Wunderluft.edm and put it into mods\aircrafts\wunderluft\shapes
Do you see the exterior model in sim?
If so, move onto the next step which is to rename things. You have to be very careful here though to make sure you don't delete " or ; or ,
Next is to look at the code.
Always do things one step at a time, don't rush in changing things here and there. Trust me I've spent many hours trying to debug errors when I've changed a lot.
It may seem like a long task to change one thing, go in sim, check it, change another, check in sim, repeat... but it is worth it in the long run.
Let me know how you get on with the exterior model bit first and then I'll talk you through the code, and then the cockpit functions.
Cheers,
Chris.