As far as frequently going off-line, that’s a defect of the SmartThings platform, and happens with all kinds of devices for multiple reasons. In most cases, the device isn’t actually off-line: SmartThings is incorrectly marking it as being “off-line”.
Sometimes a different edge driver will fix that, sometimes there are other things you can do to fix it, and sometimes it’s just an annoyance caused by smartthings. 
Usually, if you can find an edge driver with your Devices fingerprint, there will be discussion in the thread about that edge driver as to whether it fixes the off-line issue or not.
Separately, it sounds like you might also find the first part of the following FAQ helpful: