re: corian/delrin etc. drawplates.
I want to use the draw plate for wire and chain also. do you
believe that will work? That does need a bit of a taper.
fine for chain, not useful for wire. And remember, you’re
flaring the outer edge of the drilled holes. that take the place
of a truely tapered hole, and for tube or chain, works just fine.
If you insist on a better taper, after drilling the holes, you
can get a long tapered reamer that will put a taper in. You do
want to leave a least a little of the hole as a cylyndrical
drilled hole. That’s true for “real” drawplates too.
I have been real timid about using tools. Guess I just need to get my feet wet, and do it.
Dry your feet. Wouldn’t want to get water on the steel tools,
and wet socks aren’t comfortable 
For smoothing out the insides, do you believe some of the cloth backed fine sandpaper tubed and drawn will do?
You don’t need to smooth the holes in a plastic, corian, delrin,
etc. drawplate. The plate is softer than what you’re drawing, and
won’t mark it. Plus, the marks in a drilled hole go around the
hole anyway, and even in metal, wouldn’t leave a strong mark. If
you do wish to smooth those holes, though, you’ll want something
finer than ordinary fine sandpaper. For a plastic/corian plate,
I’d use waterproof paper or cloth, in maybe a 320 or 400 grit or
finer. Put a little piece in a split mandrel (a nail with a saw
cut down the length of the shank and the head cut off will work,
so you’ve got a small diameter sanding drum used in your flex
shaft. Use it wet, so the plastic won’t ‘burn’. You want any
sanding marks to go around the hole, not lengthwise to it.
Alternatives would be coarse craytex bullets, or something like
them, but you’ll have to be careful to keep it lubricated too, or
it will “burn” the plastic.
Peter