I experienced all those same issues. I don't really care about my sleep score as I'm just in it to abuse my body into giving me more coding hours. Autosuggesting tags is but a feature request and some developer attention away. As far as tagging data, I thought the whole point was so that you could keep your own metrics not that you had to. The only thing they can monitor is how well you slept. It's up to the users to correlate that with pre- and post- sleep variables. They have general comments about how to improve sleep scores, but it'd be nice if they offered suggestions based on apparent symptoms in your data.

The charger thing is super annoying, especially that they offered no avenue to recycle them instead of just chucking them in the garbage.