2)... Bruce Bump uses a 'broach' but I don't even know what that is!
A broach is a slim tool that resembles a toothbrush in profile. It has teeth on the "brush" part for scraping out the inside of a hole or slot. One maker here has made some gorgeous ones out of damascus, but he was just showing off a bit
Most guys make them out of small files, hacksaw blades, etc.
3) What rasps and files would you recommend for finishing the handle once secured.
-A four-in-hand rasp will go a long way in getting your handle to rough shape. Don't use it to go right to your finished dimensions, since it leaves fairly deep scratches. Clean those out with coarse sandpaper wrapped around a smooth bar of steel, brass, whatever to have handy.
5/6) The tang I am starting with appears to have an annealed tang as it is easy to file. It also already has a hole in it. Can I simply use a brass rod that fits this hole - or would you recommend another type of material or device? Is one pin enough - or should I add two if I can?
-One pin is probably enough on a small knife like that. Brass will work fine, if you like the color. Otherwise you can use stainless steel pins. In either case, sand the pins down or over-drill the tang hole(s) slightly to allow room for your epoxy to seal all the way around the pins.
7) Once I have the pin in place - I am sure it will grind and sand at a different rate than the wood around it - any advice on making sure the pin doesn't stay 'proud' of the wood.
-Hardwood sanding blocks or the bar you use to finish shaping the handle will help prevent this problem. Using soft sanding blocks or your fingertips will almost guarantee that you take off more wood than metal.
8) ...slow curing epoxy for these applications - any brand names of places of purchase that can be recommended?
- You can probably get away with using the "marine-grade" 2-part epoxy available at your local hardware store. Choose the slowest-setting kind they have, it tends to be stronger.