The water thing is just a quirk of capacitive touchscreens. The same happens on the most expensive watches too, which is why there is usually a water mode that you can put the watch into. It sorta locks the touchscreen until you disable it using one of the physical buttons.

I've got one of the bands (10, I think). That seems to be a solved problem. I can't interact with it in the shower, but it doesn't go haywire.

As for the heart rate, it's at least consistent. It matches what my blood pressure measurements report, and follows exercise, rather than steps.

I'm bad at breaking or losing watches. I don't buy expensive smart watches, I aim for a cheap, functional one.