A): The use of other cables with ADR cables is not recommended because there is a greater voltage drop on them and there may be communication failures. 

B): Only when it is absolutely necessary (such as when connecting a printer), where there is another type of USB-B connector and in the shortest possible length - the use of a transient reduction is ideal.

A): If a device without own power supply and higher current consumption is connected to an active power cord , the device may not work or works unreliably. If you want to use a self-powered device such as a printer at the end of the cable, no auxiliary power is needed.

B): The auxiliary power supply should be used at a higher demand than 100 mA, or when several cables are connected in series (behind each other). For details, refer to the User Manual (downloadable on the product page).