Just bought a used bike with a carbon fork having a 1" alloy or aluminum steerer (not sure which). Stem that was on there was a 1-1/8" with a metal shim. Couple questions.
1. When I removed the stem and shim, both were coated with liberal amounts of silver compound, what I assume to be anti-seize. Is it necessary to use anti-seize on stems with metal steerers, or is that a function of the shim? The fork is a Serotta F1 is that helps.

2. The entire steerer is covered with that compound, all the way to the headset. Thus, the compound was under the spacers as well. Is that necessary? Metal spacers (different brands/thicknesses) were used, but I wanted to replace with carbon spacers.

3. There's no issue using carbon spacers on a metal steerer is there?