12 reads, I guess nobody knows 
The defendable object issue iv seen before theres nothing you can do about that one just yet (bug list) the foes for some reson almost never seem to target the thing....
The Escort is a AI limit issue the AI wil only fight as long as your "Escorting" it once your dead it switches to wait mode and just stands there come hell or high watter... iv tried seting them on agreesive and they still do that so its defintly just the AI saying no hero/villan leader /wait...sad but true the computer is stupid lol
There is but one truth. Time is limited. ndnw its over
On an 8-man relentless team the mobs actually attacked a defendable object in one of my missions. It was surprising because I'd been used to this not being a big issue. We only had a few seconds to respond or else the object would have been destroyed.
Furthermore one of the ambushes didn't actually reach the truck so we ended up having to clear a whole bunch of the surrounding area in an outdoor map just to complete the objective.
I have a mission with a glowie which requires you to prevent it from being destroyed. The ambush that attacks either attacks me or sits and does nothing out in front of the object if I'm not there to attack.
Also wondering why my EB escort does not continue fighting after I fall dead, he start kneeling like a ho and gets his [censored] kicked. Its sad how he gets punked like that.