whether someone actually run the some kind of shop with hand-made CNC machine?
I assume you are asking if a home built machine can run a small production business.
The answer is yes it can be done.
The plans for Joe's 2006 and Hybrid machines as well as plans for Lionclaw's machine. These machines are strong in their design and will give years of service.
The electronics should also be reliable, Gecko's will take care of that.