Perry Aynum wrote:
I am tiling a vanity countertop, and have a drop-in china sink. The
instructions say to set it with "sealant" which I assume means caulk.
Do I need anything else, such as adhesive, or are the plumbing
connections enough to hold it in place?

Adhesive is insufficient. There should be some method for a mechanical
connection to the countertop, typically clamping devices securing the sink
from underneath.