Some very nice items. I can only give you some very basic advice. If you post the question in the main part of the forum you will get many more answers from many more people with more expertise than me. The North American portion of the forum is not very active and the connections you are asking about would be the same anywhere. Also, some of your items may be much newer than you think such as the 4000s, 6000s, and 8000s.
What I can tell you is the following. For a simple one room system, use cables called Power Link to connect the 4000s, 6000s, or 8000s, to the Beosound 3000. The Active Kits are used to place speakers in different rooms and still use the same Beosound 3000 as a source. The Actives are connected to the 3000 with a cable called Master Link. The 4000s, 6000s, or 8000s are then connected to the Active Kit. Also, there is a round 3 inch piece with the remote sensor in that connects to the Active Kit to enable the remote to turn on the speakers and the 3000. There are also “option” settings in the 3000 and the Active Kits you program with the remote.
The Bang and Olufsen web page has a large collection of user manuals. You should be able to find the manuals for the 3000, 4000s, 6000s, 8000s and Active Kits there. The other items are older and I am not familiar with them.
Hope this helps some.