I found signal to be a strength on the Moto Z Play. Weird. Low light shots are horrid on it. Either way, a style shell fits better if you remove the plastic film on the back.
I'm on the Telus network for my Z Play. My friend has an HTC One M8 with Koodo, and typically when we are in a place with very low reception I usually get messages in and can sometimes place calls where he can't.
My LG V20 has the same thing going on. I use Action Launcher 3. Launcher 3 will appear if Google is either running or in the recent apps portion when multitasking.
1) I have also had that issue. Sometimes, the phone will slow down to a crawl while doing that.
2) if you are not using the stock launcher, you can use knock on from the notification panel.
The removable battery, endurance rating for bad drops (I still use a case and tempered glass screen protectors), and the DAC. The DAC was why I got this phone over the Axon 7, and there are more things that I can do to the UI that I really enjoy having.