Kernel + rootfs for Qt5 development

Hello, colleagues.
I use one BeagleBone Black device last year - but I had very surface knowledges about it works.
I’m using 3.8.13-bone70 kernel with something debian rootfs (from cubie, as I remember)
I configure it for 1920x1080@50 HDMI output - all worked and work now.
Now I builded new kernel 4.1.15-bone18 with SGX drivers (great thanks for Robert C Nelsof for him work), it works, my application builded via Qt5.4.2 show image on monitor, handle usb mouse via evdev, but I have three problems:

  1. I can’t set resolution 1920x1080@50 (at 3.8.13 kernel I used next kernel parameters: console=ttyO0,115200n8 video=HDMI-A-1:1920x1080MR@50 root=UUID=9b4ac273-ac16-4104-9408-be99ed8ec0eb ro rootfstype=ext4 rootwait fixrtc quiet init=/lib/systemd/systemd).
  2. I can’t power off bbb - now it shows message “System halted”, but device stay with power.
  3. I can’t start my Qt5 application from non-root user: in this case I have message - “Could not initialize egl display”.

I’m understanding that I miss something important, but I can’t solve there problem all last week, so I hope that some new thinks will here.