A few questions regarding water, flowers, and marijuana

[Brian W.]

Should I tell tenants that it behooves them to notify me of a water leak immediately as it costs them money too? From what I've experienced and observed, water is the biggest source of damage to a home. I would like to prevent water damage as much and as soon as possible.

Should I consider giving flowers or some other welcome gift to new tenants?

Am I responsible in any way for tenants dealing drugs or growing marijuana in one of my properties?