Yes but there are also 3rd party tools available to code ECUs, keys etc. Like the VAG-COM for VW and Audi cars. I don't need to ask vw's permission to add a new key to my car.

Actually you do need to go to a VW dealer to get a new key paired to the immobilizer. It's been that way since at least 2002.

Edit: http://www.myturbodiesel.com/wiki/key-and-remote-replacement...

Tldr: You need the SKC to do it, only VW knows what the SKC is. Or you can hack the immobilizer.

Yes, and if there's a problem with your car that needs an ECU firmware update ... you tend to have to have that done by an authorized dealership.

Not if the update is released. You can buy a cable from China and download the software to do the update.