Hi Wernerfe
I'm not with Laminar Research, just a fellow simmer in the UK, but the short answer is yes, the entire root directory of X-Plane 10 is standalone and can be transferred from one PC to another by copying and pasting.
However, it is important to note that you can only use one copy at a time whilst online i.e. one product key per valid version of X-Plane 10 being used. Please see the following link:-
https://www.x-plane.com/product/x-plane-10-digital-download/
If you start trying to use two versions of X-Plane 10 online at the same time, LR may revoke your licence?
It is the same for X-Plane 11!
Question: why do you wish to purchase X-Plane 10, when X-Plane 11 is far superior?
Regards