I've got a Unimat SL, a wonderful old gadget that can be set up as a lathe or a drill press. Last year it celebrated its 30th anniversary in my possession; back in 1975 it cost about $250 - a huge outlay for a struggling grad student. I bought it through the hobby shop where I was working; the owner let me pay him in installments. Nowadays, if such a tool were available, it would cost at least twice as much. (The Sherline lathe, with a second motor to turn into a drill press, probably comes closest.) The old Unimat is on its second motor (the first one died in about 1983), but it still works fine.
It's capable of making belaying pins all right, but since I had a bunch of the Bluejacket ones on hand (they were a lot cheaper in those days, too) it made sense to modify them rather than start from raw brass stock. It actually didn't take long - less than a minute per pin, once I got the technique figured out.
Wire-cored plastic rod probably would work all right, but I've never seen it in sizes that would be small enough. About the only material I can recall that meets that description is the stuff made by Plastruct, and if I remember right the smallest diameter is about .040". When it comes to turning, it's hard to beat brass.
A lot of considerations ought to go into the choice of scale for a model. I tend to gravitate toward smaller scales, for a couple of personal reasons. I'm near-sighted; I have trouble recognizing my wife from across a room without my glasses, but until recently I could do all the work necessary on a small-scale model without resorting to magnification. (During the past few years I've had trouble getting both eyes to focus simultaneously on anything closer than about a foot and a half, and I do find magnifiers helpful sometimes.) I've also discovered over the years that my finger muscles are far better coordinated than my elbows. When my father and I were remodeling our old house he used to get impatient with my inability to drive full-sized nails without bending them, but I don't have any trouble threading a needle with one hand. I also get along far better with a 5/0 paint brush than I do with a 2" wide one.
One of the great virtues of ship modeling, in my opinion, is its tremendous variety. I've always tried to resist the temptation to think that one form of it is "better" than another. I have tremendous admiration for the grand old English "Board Room" models on 1/48 scale, and equal admiration for Donald McNarry's astonishing models on 1/196 and 1/392. It's the kind of hobby one can literally work on for a lifetime without exhausting even a small fraction of its potential.
Youth, talent, hard work, and enthusiasm are no match for old age and treachery.