As an Idea I think you can improve on 2 things..
With the water pumps include some extension cables like Noctua does for their coolers..
At least an extension and a low-rpm (the one with the resistor) for when someone runs their pump from a molex connector... I certainly was not expecting a 5 cm long pwn cable on the pump when I ordered it and now I have to wait some more till the order for extension cable comes.
I know for a start that it states in the description of the product this and what not...but by including some "start up options" from the box would be terrific on the consumer side.
The 2nd thing... If you could stick some labels on the top of your monoblocks to state clearly "Inlet" "Outlet" and "remove before use" would be great and will reduce greatly frustration of getting it wrong..
Again will improve customer satisfaction