I turn at the highest speed my lathe has. Given that I don't pay much attention to just what speed that is I am going to say close to 3000 R.P.M.
I have a mini metal lathe that has a top speed of 2700 R.P.M. and I know my wood lathe is moving considerably faster than that. I even rough turn the blanks at top speed. the only thing I slow it down for is to apply C.A.
I use the CA for two different steps with my pens. one as a filler using sand paper and the ca rto make a paste that fills all the little pours and will fill some pretty big ones as well. then I sand all this down smooth and even polish the wood so that the catoyance shows. then i slow the lathe down again and use wax paper to smooth the glue on the blank as it slowly turns. putting a coat of wax on the bushings and mandrel keeps them from sticking. don't hold the paper to the blanks for long it will stick just get the glue spread the smoothing and polishing comes later. once it is all dry start sanding. I can usually start with 400 grit. sometimes 320. and I work my way all the way up to 12000 micro mesh. polishes like plastic. but be careful with the sandpaper you don't want to sand through the CA.