No, ill try to tweak some values, but to play at 5040x1050 i dont think itll be possible since you cant launch Arma 2 at this res., just at 3840x1024, and then change in the video options menu to 5040x1050 - and this resets, at least for me, any ui changes.
The HUD issue is fixed, easiest way possible haha :D, simply edit your ARMA2PROFILE at C:UsersHomeDocumentsArmA 2 or C:UsersHomeDocumentsArmA 2 Other Profiles , setting :
BI finnaly fixed that D3D error you got when trying to launch Arma 2 at 5040x1050, try the latest beta patch (check the readme file of the patch to correctly install / run it) :