In regards to pin names my suggestion is to use the built in linuxcnc parallel port config creator and set it up for your machine.
Then copy the pins for the io and other bits into the remora config.
Then just replace the parallel port pin names with the remora ones.
Understand you are asking for alot of a what I would call alpha stage project.
Once it gets it's into late beta is when it will have more hand holding guides and configs for users of lesser abilities.
To find the pin names if they are not spelled out for you just read the code to find them.
If you are unable to grasp even the ability to read code I suggest you wait or try a different solution.
remora-docs.readthedocs.io/en/latest/
This is the documentation for the spi version of remora that uses 3d printer main boards.
This may give you an idea of pin names.
I use this version and not the ec500.