The NI Service Center will continue to support older operating systems and older Native Instruments products. Products released with or after KOMPLETE 11 will be supported exclusively by Native Access.
At launch, in August 2016, Native Access supports all KOMPLETE Instruments and Effects (from KOMPLETE 9 onwards) and MASCHINE Expansions. Support for further products, including MASCHINE and TRAKTOR software, will be added successively.
Yes. When you register your hardware, Native Access will automatically scan your account and register the included software. If Native Access doesn’t know that you have the hardware, it can't provide your software.
Yes. The first time you install something using Native Access, you will be asked to confirm the default install location of your products. You can provide separate install locations for applications (MASSIVE, MONARK, KONTAKT, etc.) and their respective libraries where applicable. It is strongly advised that you install all your sample libraries on one hard drive. If your computer's built-in hard drive is not big enough to store all the samples in your libraries, an external hard drive is recommended.

For further information, please read this Knowledge Base article to learn how to customize install locations.
No. Native Access lets you choose which products you install and when.
The end user license agreement (EULA) for Native Instruments products allows the simultaneous installation on two computers (three computers for all versions of MASCHINE and KOMPLETE), as long as only one installation is used at any given time.

It is not necessary to 'deactivate' an existing installation in order to activate the product on an additional computer, but due to the license agreement, you're required to uninstall the product from the previously used computer.

Please note that Native Instruments reserves the right to disable an account or serial number if it has reason to believe that the license agreement has been violated.
Native Access requires an internet connection in order to install and update your products.