- There's a magnetic connector (like mac boks) that hooks up to USB. It doesn't come with a wall connector, just USB, which is a bit weird.
- It does indeed look like you need to press a button to start tracking sleep.
Other fitness trackers have automatic sleep tracking, even it's only heuristic based. For example misfit just has the formula of 'if not moving much for a large chunk of time in between these user configurable hours, mark that as sleep time'. That is a huge improvement.
The basis band seems to have a more advanced automatic sleep tracking algo. You guys would be probably interested looking into it.