#7 All I can do is relate my experience getting started in pen turning. The only lathe I had at the time was my ancient Craftsman 12x36 metal lathe. I used the only cutter I had--a stub of HSS cutter mounted in the lantern style tool post.
This actually worked rather well, for the most part, thought it was a slow process. I had a mandrel chucked in my huge 4 jaw self-indexing chuck with a live center in the tailstock.
The metal lathe is great for straight cuts--any profiling is more of a challenge (not, I suppose, if you have a CNC machine). If I wanted a bit of belly, I'd cut in steps, or try to "etch-a-sketch" it by moving the cross feed manually with the carriage drive enabled--tricky. I also made much use of my files and sand paper to get to the desired shape.
Another challenge, especially with more brittle blanks was that you're pretty much forced to begin the cut at the end of the blank--something you don't do on the wood lathe. This forces one to make rather small cuts and makes progress slow. Can't recall if I tried circuit board blanks, but I do recall I did some Inlace Acrylester which is always a challenge. If you can avoid catching the end of the blank, there won't be any chip outs--if you do try to make a cut a thou to deep, brittle blanks are easily destroyed this way.
So, yes, you can do this. It will leave your oily metal lathe covered in a paste of sawdust, shavings, etc. It will also be slow and frustrating. Again, this is all my experience with my old lathe. A newer CNC lathe would, I think, be much better albeit at a cost.
These days, my metal lathe is used for drilling, squaring, applying CA finish, and for pen assembly. All turning is done on my wood lathe.
Hope this helps--YMMV.
Regards,
Michael