Hello, I'm the guy who designed the linistepper.
I have no idea about your "Error writing PIC id area" fault code. The ASM code on the page you linked to has been used by hundreds of people and is fine, so my guess is that it an issue with your programmer, or how you setup the options/config in your programmer software.
Re the "enable" pin, if you look in the top of that code, the comments state "but POWER is now "ENABLE" (active LOW)" so the ENA pin needs to be at 0v for the motor to run. DIR pin will not matter, it only changes the direction the motor turns and nothing else.
You need to apply DEBOUNCED pulses to the STEP pin to make the motor turn, generally a 555 oscillator etc is fine. Pressing a button on the STEP pin will cause problems due to button bounce.
If you are using a 2pin xtal at 16MHz you need to add two 15pF caps to the PCB, you can solder these under the PCB between the 3 pads, with the middle pad being ground of course. So one cap from middle pin to the outside pin.