Tangential Cutting Path - Post Processor/ Filter File?

Hi Friends, 

I've spent the last few months modifying a chinese cnc with a mesa 7i96s and a custom cutting head I've made with the end goal making it a tangential cutter  I've long dreaded this part because i simply do not know where to start. I am working on tuning the error in the cutting motor but this is next on the list.  I am going to lay out what i would like the machine to do, and hopefully you guys can point me in the right direction. 

Attached is a cad screenshot with a visual of the cutting head. There are two pneumatic cylinders that can deploy the cutting head down or up with a solenoid valve controlling them both. I wanted to leverage some of the 7i96s auxiliary outputs or the torch up/down to control this valve. 

I am not sure what cad program that will be outputting these, probably fusion or solidworks in the long run so i am leaning towards a filter file or i guess this is technically a post processor, as mentioned in this post, but i didn't see really any progress so here i am. 

forum.linuxcnc.org/38-general-linuxcnc-q...n-of-travel-possible

My fundamental issue is i don't understand what node is doing what. I haven't ever uploaded a file to LCNC but i imagine its Gcode. 
So my simple brain wants to understand;
- Cad program - > outputs generic 2D gcode
- **NEW FILTER FILE** -> magic happens here?
-LCNC - > doesn't know the difference, its just following orders. 




Requirements (will probably grow):
-be able to set "cut depth' (the z position with 'torch down')
-set cutting motor to only find angle in one direction (not sure if i can or should do this on LCNC and not the filter file) because belts aren't very good pushers.. 
-I'd like all travel movements and find next angle to happen with the torch up, and it only go torch down only when the next angle is good and its in position
-BUT i would like arcs and angle to be smooth, i need to differentiate between lines with arcs an endpoints. 


also sorry i am rambling, can you tell i've thought about this.