Not being in the industry you don’t have the slightest idea of what you are talking about.
Putting aside the necessity of cognitive reason in some tasks (the LOUD dirty cutting of the stone must be accomplished AROUND funerals and visitors) Any ONE of the separate tasks can be done by a machine and the main task already is (actual blasting of the stone albeit in factories)but once you try to put ALL of the tasks to one machine you have an impossibly complicated and huge machine and even then it CAN’T EVER BLAST AS FAST AS A MAN thus making impossible any hope of even getting past five jobs a day.
Very few cemeteries would allow a machine of any size to drive over the graves since the weight of even an F350 superduty with compressor will collapse the graves and eventually get stuck.
It will happen that people will be to poor to provide for tombstones before I will be automated out of a job.
Being in the software industry, and just generally nerdy, I know how many of the tasks you outlined we ALREADY have machines doing. Finding a specific location is easy the Death Valley test hasn’t been passed but the attempts to pass it could easily navigate a cemetery. Removing obstructions and getting the stone out, most of the strip mines in the country are doing that right now, with things much bigger and heavier than your 1200 pounds. Assessing free space on the stone with regard to adding content and adjusting to fit, the computer you’re sitting at right now has software that can do that. Making the template, cleaning the stone, afixing the template and carving is something every custom bike shop in the world has equipment to do.
It’s just a matter of putting it all together, and that’s not that tough. The only thing slowing it down is that it would be more expensive than you so it’s not worth the expense. But eventually your wages will climb and the cost of the machine will fall. The weight is the least of the problem, the key there is big wheels (like mars rovers), spread the weight over a larger area, less crushing.
We’re really looking at 5 to 10 years. The equipment exists, they just need to adjust the cost and have a reason to do it.