The water is condesation. Won't hurt anything.

The carb kit has a needle and seat and accel pump diaphragm. The main benefit is the opportunity to blow out all the passages well. and readjust the float level and inspect the secondary actuator diaphragm. The kit may also have a couple of other bits in it, but not much. Ebay or dealer for the carb kit - pretty cheap. It's easy to rebuild except for getting the choke linkage loose from the top cover. Not all that tough, just finicky and little parts.

Not responsible for advice not taken...