A1-  

I don’t believe that there is a specific grade level. Students can master different skills at different ages. Perhaps they have opportunities in which you evaluate their proficiency and determine if they are ready to do so. They can earn a badge and get certified.

A2-  

We’re still waiting for our Glowforge, so I can’t completely address this – however, we have a large X-Carve CNC router, which is somewhat similar. Between learning curve for the design software (Inkscape) and setting up the material/machine for cuts, it’s been limited to our 8th graders for independent use (so far).

A3-  

It depends on the machine…but high school is probably the earliest in which more students have the capability.