Das sieht so weit gut aus, das aktuelle Farbwerk 360 hat allerdings zusätzlich auch die Mainboardanschlüsse für 3-Pin 5V aRGB LEDs, da bräuchtest Du also keine Adapter.
Der highflow NEXT muss auch an einen USB Header, hast Du nicht genug kannst Du einen internen USB Hub benutzen.
Die Pumpe kommt, je nach Pumpe, ans Netzteil und einen Lüfterheader, wenn es eine PWM Pumpe ist kannst Du sie an den OCTO hängen, wenn es ein 3-Pin Anschluss ist ans Board.
Beim GPU Block kommt es auf die LEDs an, sind es 3-Pin 5V aRGBs kannst Du sie mit dem Adapter an den OCTO hängen, sind es 4 Pin 12V RGB LEDs kommen sie ans Board.

Ok, yes aRGB and DRGB means the same. 5V individually adressable LEDs, it is the standard WS2812B.

Not really correct:
The RGBpx Connector of the HighFlowNext is an ouput, same as on the Farbwerk. You may not connect these!
The same for the 2pin temp sensor. It is an input on Farbwerk and HFn. You cannot connect them.
Additionally, you cannot use 8 connectors of the Farbwerk. You may only use one connector per channel, so a maximum of 4 connections here.
If you need to connect more, you need the rgbpx splitty.

You also may want to consider which RGB devices you are connecting to which RGBpx ports. You have 4 RGBpx ports on the Farbwerk360, 2 on the Octo, and 1 on the High Flow Next. These ports are not all equal. In Aquasuite, the 4 ports on the Farbwerk360 can have up to 20 concurrent LED controllers active. An LED controller can be assigned to more than one place through the Multi-Assign function. You can have up to 60 of these. The biggest thing is transparency. In Aquasuite an LED or group of LEDs can have multiple RGB controllers assigned. They appear in a stack and the topmost controller prevails. For Farbwerk360 ports, you can set a transparency level for each primary color. This allows patterns/colors from controllers lower in the stack to “bleed through” the controller higher in the stack. It’s kind of hard to explain but it allows multiple controllers to affect the LEDs at the same time which is a very powerful feature.

The RGBpx ports on the Octo are more limited. They do not support transparency. Instead of 20 concurrent controllers, there are 6 per port. The Multi-Assign function is not supported. The RGBpx port on the High Flow Next has slightly different limitations. You can have up to 8 controllers active – 2 for the 10 built-in LEDs and 6 for the RGBpx port. No Multi-Assign function. So the RGBpx port is the same as those on the Octo but control of the 10 onboard LEDs is more limited.

Another thing to consider is that while the 4 ports on the Farbwerk360 will run in sync, there is no sync between them and the ports on the Octo or the High Flow Next. If you have 2 Farbwerk360s, they will not sync with each other. I learned this the hard way. Due to these functional differences, you may want to use the Farbwerk ports for RGB fans Distro, and LED strips. For devices like the GPU block and CU block that only have a few LEDs in them, the Octo and High Flow Next RGBpx ports may be sufficient. Whether port sync is a factor depends on what presets you are using or however you end up customizing them.

All of this is detailed in the Owner's Manuals. I suggest you download them and read through all of this. You will also see the differences in Aquasuite.