I think I went over a year before I ever saw one of my snakes drink......no big deal. Provide the water and it will drink. Unless you watch the snake 24 hours a day, chances are there is alot that you do not see.

3 weeks is no time to worry about feces. My ball python goes about once a month or so...sometimes longer.

Handling during shed is up to you, but most would recommend not to handle. The snake may be defensive (it can't see well) and handling can cause unwanted stress.