First, there is not enough space to detail all the questions you ask
A chisel will only perform to the level at which it is sharpened regardless of what it is made from!
I'm using full-size chisels for pen-turning because they were cheap at HF when I bought my lathe. But they're a little unwieldy for small work and after turning several pens, I feel like smaller chisels would be better. I see three options:
1. Standard HSS chisels;
2. Standard chisels with carbide tips (like the 3 pc set from PSI for $59); or
3. Interchangeable carbide tips which usually have a square tip for roughing and a round tip for finishing.
I'm looking for pros/cons on these options from all you experienced folk. I expect to turn a lot of non-wood (acrylic, trustone, M3, etc.)
thx, rink.
If you are wanting to know HSS vs carbide that is a very treacherous topic and and must tread carefully.
Carbide tips is designed for metal use but managed to find it's way to wood turning. There are also some applications where they cause more problems than not. Some will even tell you they contain magic properties and you never need to sharpen then, which to is not true. Everything wears out over time and use which means they are not an excuse to not know how to sharpen.
As for size goes you will find the longer the chisel the more stable it is. Depending on what you are turning you do want something stable. One of my gouges is fairly small but it's one of the longest chisels that I have and it is superb.
I would suggest that you get a few chisels to finishing work. That way they will last longer and need less upkeep. Fact is a chisel sharp enough to round the blank is not the same level of sharpness needed to do the final trim and detail work.
A sharp high carbon chisel will out perform a dull carbide tip chisel any day of the week. The reverse is also true, A sharp carbide tip will out perform a dull high carbon chisel. Factory sharp is a contradiction in terms

Think of them more as somewhat properly shaped vs being sharp.
Bottom line here is this, it really does not matter what the material is. What does matter is how sharp is it and how you use it.
http://www.penturners.org/forum/f14/sharp-japanese-waterstones-111876/
Did you buy the red handled harbor freight set? They are excellent for the money.
They are mid sized tools. I think the right size for pens. The carbide tools are about the same size.
I have the sorby micro set as well. They only see occasional use.
I use three tools for turning pens. Really only three and I use all three daily for pens.
1.- wide spindle gouge (roughing blanks to round - and then some for some blanks.)
2. - oval skew. Love love love it.
3. - easy pen turner carbide tool. The go to tool for acrylics after rounded. In my limited experience with them, I can round an acrylic blank much faster with the big spindle gouge than the carbide. After round or close to it, it's mint.
For fragile wood burls, I pick the skew over the carbide.
I recently made up an epic sharp finishing oval skew and sent it to Ed at exotics for him to try it out. Maybe he will chime in and give some info about his experience with something that sharp. It was very sharp, like 10,000 grit sharp. Which means you really do not need to use sandpaper after using the chisel.
They are light colored handles, about 12 inch or so. I've been knocking the corners off the blanks on the belt sander before turning...way faster than turning the corners off. Gets the blank to about 75% round. Tried a skew couple times...didn't work so well, need way more practice with that.
How about a chisel that could go from square to round in 1 maybe 2 passes? (one pass being left to right and back to the start)