It's alive !
Finally, the first lines of firmware have been written and the the barebone gantry is moving sweetly. We are more and more leaning towards GCode (or a subset thereof). Many people have commented on this and tried to push the community in that direction -- maybe rightly so.
Our initial hesitation was that GCode seemed super messy and bloated for the lasersaur. After taking a look how reprap-related project use a subset of it we think much higher of it.
Reading through the source code of grbl and fiveD is also super helpful. Still if somebody knows of a technical paper on stepper motion, acceleration, deceleration strategies we would use it as our night time text for the weeks to come.