I've had a pair of Huawei FreeLace Pro for about a year now, using them with an iPhone, and the only issue out of those you described, I experienced, was the "re-pair once in every blue moon", which is an issue that seems to be pretty universal across bluetooth devices.

They support multiple devices, but no automatic switching, it's just a button short-cut to switch between them, works quite nicely for switching from my iPhone to my iPad and back.