Any speed you want if it works for you.
BUT, Drilling - slower towards 1000 give or take 10 to 15%.
Sanding, Slow as I can go, . . . becasue with high speed - it will wear out MM quick or burn the CA causing white "diggs" on hardened but not yet cured CA. The CA will melt in a spot, ball up and and cause scratches, in this case.
Buffing - for me higher speeds but ONLY if the CA is cured, not just hardened.
Turning from Square: For me - as fast as I can but with tiny bites until one portion/section or spot is round and then move down the line slowly.
ON occasion with particular segments with woods and metal, as fast as I can for the final turns. With a just sharpened blade and hard or stabilized wood, light cuts on the final turning will or can leave the wood/segments as smooth as sanding does. This will eliminate the need for sanding and prevent sanding dust from smearing on the wood portions.
CA applications - slow
I have a Rikon with a PSI VS. LOVE that VS!