The tip touching the cloth is from a natural follow through when using the pendulum stroke and not from an elevated cue while stroking. As the pendulum swings up during follow through, the natural path is toward the cloth after CB contact. In theory, anyway. Other than when learning fundamentals and forming muscle memory, when everything is exaggerated, such as the pause from backstroke to forward stroke, I'm not sure the tip touching the cloth every time is a standard. But some instructors do teach and advocate having the same finishing position in your stroke for consistency. I agree, although admittedly, I don't always complete my finish.
Dropping the shoulder will vary person to person in terms of preference as well as effectiveness. It without question introduces more muscle mechanics into the stroke and therefore is a more complex stroke. I try not to do it, but if it works, it works.