Well, I'll provide technical support here as well.

Just getting the ropes, but I have crashes on Win7 64 bits
That should definitely not happen. I suppose you managed to get the thing installed (it couldn't crash, I presume, without that first step. Which version do you have installed (main menu, upper right hand corner)?
I doubt I will learn much play online, my life expectancy would be around 10 seconds
You may get surprised. Just give it a try and ask for a tutor. There are lots of guys around willing to give you some orientation. Be sure to have familiarized yourself with one vehicle however, e.g Leopard 2 or M1A1.
Can you tell me if the dongle could be infected by virus?
I don't think so. The CM stick uses the USB mass storage device
driver, but it has no user/operating system accessible storage space (which would be needed to infect it).
It would be helpful to know if the crashes occur under certain circumstances (with specific vehicles, in specific situations, with certain scenarios) or if they happen to be completely random. Do they occur in fullscreen mode, or also in windowed mode. The more details you can tell, the better I can help.