1. Several times I have powered down and restarted and the phone continuously tries to restart at the Motorola logo. I think this is called a boot loop failure. The phone continuously tries to get past a point, fails, then tries again, fails, and so on until the little android guy shows with "no command" under him and it stops there. I got past this by doing a soft reboot. Press and hold the power and volume down button simultaneously until the screen goes blank. Once the screen is blank, let go of the buttons and the phone will reboot and get past the boot loop failure. This is what you need to do if your phone freezes for any reason, it's how you disconnect the battery since you can't remove it.
2. Wallpaper moves on the back of my screen, annoying to me. I suspect this is probably so you can move to the correct spot and paste it somehow but for now I got around that by picking my spot, taking a screen shot, and using that as wallpaper which won't move.
Other issues from the Lenovo community that I haven't had any issues with are: turbo charging is slow, notification or phone sounds not working, short battery life and overheating, camera freezing, fingerprint sensor not working, long hang times, ghost touch, play store not downloading or updating, and google music quitting mid song.