All Orchestral Tools collections are completely separate and may use different, incompatible Capsule versions. Therefore is is not possible to integrate Expansion Collections into their respective Main Collection. Do not attempt to copy an expansion into its Main Collection's folder structure. This can result in severe issues and especially on OSX can make your installation unusable.
All patches from Expansion Collections need to be loaded via Kontakt's Files tab or through the operating system's file manager.
NKS primarily serves to map keyswitches and controllers to the Komplete Kontrol keyboards. This works well with pre-defined controller sets, but is of little use when everything is highly customizable. Since in our collections everything is customizable and there are no fixed keyswitches, etc... NKS has little benefit.
Of course all OT collections can be manually mapped to keyboard controls. And of course NKS only applies to people who actually own a Komplete Kontrol keyboard - it is not useful to users of other MIDI Controllers.
No, the horns in Berlin Brass are completely new recordings, played by other musicians on different instruments with a very different sound and concept.
No, Orchestral String Runs and Berlin Strings are completely different collections recorded at two different locations which do not share any articulations.
OSR is focused on String Runs (hence the name) and offers a great variety of different runs and figures.
BST is a full-featured string collection and focuses on regular articulations. Both collections work very well together, though and OSR can add a lot of tonal colours to BST.
The Soloists Series (Woodwinds and Nocturne) provides dedicated solo instruments intended for exposed solo passages on top and leading any musical background - like a soloists standing in front of the orchestra. All Soloists are recorded dry at the Teldex Solo Booth and have a Teldex IR for placement.
The Berlin Strings - First Chairs represent the section leaders (solo players) within the orchestra. They sit in their orchestral seating positions and are intended to serve as a "string qartet" within the orchestra as well as (primarily) enhancing definition within the section. The Berlin Strings - First Chairs are recorded in the Teldex Scoring Stage and fit great together with all other "wet" Berlin Series and Metropolis Ark Series collections.
Nocturne Violin and Nocturne Cello also have a huge number of legato styles (14 to be exact) with a large number of sustain types with baked-in expression, etc... The Berlin Strings - First Chairs are much more bare-bones and use a single legato style plus optional portamento with three sustain styles.
Berlin Strings - First Chairs and the Nocturne Series are very different. They complement each other nicely, but neither can do what the other can. And of course they do not share a single sample.