The pin numbers in the documentation do correspond to the physical pin numbers of the parallel port.
The 5 input pins 10, 11, 12, 13 and 15 have the identical circuitry. The assignment of functions, X LS, Y LS, etc is the conventional standard used in the CNC world. You could chose to rearrange them as long as to change the MACH3 screens to match.
The 12 output pins are a bit different. While they all are buffered and appear on the terminal strip, several have additional circuitry.
Pin 1 also connects to the PWM to analog converter used for spindle speed.
Pin 14 has 3 buffers so it can drive multiple stepper enables.
Pin 17 can be jumpered to the relay usually used for spindle enable.
Pins 1, 8, 9, 16 and 17 are not used by your application and could be used for additional functions. For example, Pin 17 and its relay could be used to operate the chip vacuum as the coolant function of MACH3.
Start up and test the steppers one by one. The Y axis appears to be the heaviest and will determine the max speed of the system.
https://www.machsupport.com/forum/index.php?action=dlattach;topic=43939.0;attach=54790;imageRemember the 1.5A current setting is a guess, check for overheating as you tune the motor. Changing from 1.5A to 1.0A will halve the heat. (Watts = current
squared times resistance)Since you will be operating in a hot environment you could begin at 1.0A and see if it gives satisfactory performance.