Stange open source amd graphics linux driver problems

[Gameborn]

Mine graphics is gcn2-based r7 integrated graphics on a10-7850k

at first, it supports only opengl 3.0 while officialy it should support 4.3 (both on Ubuntu's lts version and arch's latest)

Second, gnome is laggy but it isn't big problem because any other de (including gnome-based unity) works perfectly,

third, strange problem in minecraft. When world in loading(in multiplayer in minigames it happened frequently), it sometimes get stuck on loading screen and should be closed manually. And overall, framerate in games isn't very good, but that's excepted so I don't complain.

and latest, some freezes both in games and overall desktop usage (for example in web browsing)

Amdgpu-pro don't want to work on ubutnu 16.04.2 (while older version worked on 16.04.0) and I want to use arch (just like it's ideology more).

old catalyst driver isn't supported and require old kernel as well as xorg, but when I used it back on 14.04 it worked fine (except tearing) and it supported opengl 4.5.

What's can be the problem?

And I know, amd video driver on Linux is bad thing. But maybe some patch for open source driver or workaround for amdgpu-pro (possible to move to Ubuntu just for that) to work?