If the scouts hid in these ruins, does that confer a 2+ cover save as a result?
Yup, I do this with my Imperial Fists. It's great right up until a flame template hits them, but what can you do.
If someone uses an ADL with quad gun, assuming the building is large enough, can the quad gun be emplaced inside the building, as long as the ADL is connected to the building (i.e. placed next to it?): It was a puzzling question a few weeks ago during a game I watched, and no one could come to an agreed decision
The rules for placing gun emplacements in the new Stronghold Assault book states that they gun needs to be within 6" of the fortification if was bought for. Specific wording/thread here.
I would wager that if you really wanted to place your QG so that it gains cover from the ruin you could provided the gun was still within 6" of it's defense line. Just remember that you may also end up providing your enemy with cover as well since you could potentially be limiting your own LoS. Given this point,
basically the fortification goes in first, then other terrain around it
it would be very hard to get your fortification down and then a ruin close enough to it following the rules for placing terrain for this to be achieved, so basically it shouldn't be coming up too much if you're doing things the GW way.
(alternatively assemble the table then replace terrain with your fortification if playing at an event with preset terrain).
Dude, that is a great idea. It will certainly save time when I'm on my way over to a buddy's for a quick game and he has to wait for me to get there with my ADL to set up terrain.