I recall my time at gunsmith school back in the 70’s and 80’s and some advice and comments from instructors on your situation. Then I think about your questions and the gunsmith friends I've known for forty years out West, in NH and NC and in the final analysis there is no answer. The only thing that is a constant and that is the fact that about 75% of the time gunsmiths lose money. If you're financially solvent then pay for some good E&O insurance and enjoy yourself. But if you need a reliable family supportive income then I'd think twice or maybe three times.
In school they warned or advised that there really isn't such a thing as a good reliable walk-in gunsmith business there is only walk-ins that eventually suck the hours off a clock. In this age of internet business your UPS man is your best friend. That the only reliable business comes from word of mouth, some advertising at shoots, at clubs etc. and the best is having a gun writer in your corner or known match winners using your product. After that the best income, if you have machining skills, tooling, and an inventive mindset is to design and build a gun related product that can coexist with general gunsmithing work. Ron Power and Hamilton Bowen are old friends of mine and both have proven this formula but there are plenty of others like Jim Clarke/Jerry Miculek, Weigand, etc etc. all big names but there many more you never hear about who are doing well.
Not totally relevant since I got out of the business many years ago but I was a revolver mechanic building raceguns for plates, pins and other comp events in general. But walk-ins and law enforcement people about killed my business. It was people hanging around looking and continously prodding with questions and never generating a work order or cops looking for freebies. I and a number of my gunsmith friends had to go nocturnal. Close the shop during the days with only two half days open during the week. Posted hrs on the door. If you can do it then it works for one or two person shops. Of course if you have counter help or a secretary to mind the gates that's different. Anyway all the best of luck to you. The business needs good honest mechanics