To remove the MG,
http://www.coh2.org/topic/17610/need-help-infantry-not-deleting
As far as the icons, this is on my list too. One of my maps suffers from this, but it doesn't go away after a few seconds. I just haven't taken the time to look into it yet, as it doesn't change game play.
For the buried bunker, make the object a visual, that should fix that.
If you select the engineers who were to build the wire, and hit the stop icon, do they go away?
Yeah this method seemed to of got rid of the MG.
The icons seem to stay sideways for a random amount of time from what i can tell but yeah it doesn't affect the game so its not a big deal.
I tried switching the buried bunker to visual but it's still repairable ingame.
Nope the ghost of the wire will stay there the entire match no matter if the engineer unit has been told to stop retreat or even if they die.
It only happens when placing it that way in the image with one barbwire in the red on each side otherwise it works fine but I've never seen or heard of an issue like this before.