I removed the Colt M4 pack and it resolved the freezing while taking damage or under fire issue for me.
May 10 2016
I have also saw this in my game as well. As soon as I'm hit the game stops responding for a short time. I drove a vehicle down into an area with several enemy AI and the game became unplayable for more than 45 seconds. It took a while after I respawned even for the game to smooth out again!
I agree that this only started happening after the latest patch.
There is a third party website that does just this, called Armaholic. It's been around forever and is used by almost all of the arma mod community. http://www.armaholic.com
May 9 2016
The in-game interface is fine now with the user being able to reposition them but the out of game menus and the editor menus are still clipped behind the monitor bezels.
Other games allow the outside edges of the menus to be moved. Much the same as resizing a desktop window. (not to the same extent of course) Could something similar be implemented in this case?