Hi,
I see now why you had all those outputs set, the instruction tell you so. Note that ouput#2 and output#3 the port for both is zero and the pin for both is zero.
Clearly the manufacturer had something in mind, unfortunately I don't know what. My guess is that all those outputs, enable and outputs#1-3 are to activate
the four drivers. SW1 on page 6 controls the activation mode for each driver. The pic shows it set on Auto (L), may I suggest changing it to Manual (H). So change
SW1 only.
The microstepping is set to 2, that 400 pulses re rev. 400 ppr/10mm pitch =40 'steps per'. So the setting recommended will work. Half stepping (microstep=2)
is pretty course and may at a later date be changed but it should work as it is.
These Chinese controller/driver boards have a poor reputation, many of the most experienced CNCers on the forum don't bother responding to requests for help
with these boards. If one or more of the motor driver chips fail then the whole board will need to be replaced. There is a high probability it will happen.
If you do replace it don't buy more Chinese junk. Do some homework BEFORE you buy.
Craig