I am somewhat confused by your question. If you are asking if the car's immobilizer protection is left in place, then the answer is yes. Unlike many other systems, the stock ECU is left untouched.
If that doesn't answer your question, please let me know.

 

Here is more info on the FCON

http://www.hksusa.com/categories/more.asp?id=1933

 

I would say flash is better...ECUtek personally...no piggyback "tricking" your ECU...

 

By itself it doesn't work with the stock knock sensor but it can be made to function with it, for no other reason than making more money through hardware sales. Look for this product called HKS A/F Knock Amp.

 

I just installed the Xede, and it was definitely worth it. The installation was a breeze, it took me all of 45 minutes being super careful. I ran into an issue where I was trying to run it before the map was loaded, but I called Vishnu, and Shiv hooked me up. He e-mailed me the map I needed for my car's setup (Turbo-back cat-less exhaust & 93 octane), and then he walked me through the upload process which took all of 20 seconds to do. (As long as you have a laptop.) The difference in power is very noticeable. Vishnu and the Xede are both awesome!