I think yer kinda screwed as far as knocking out the wall now. Ya shoulda never asked her if ya could. Otherwise ya coulda done it and then just said "You never said I couldnt"...haha
It may seem like each individual point is a past issue, but its not. It will all be brought up again, someday.
ok. how about just cutting a small hole in the wall like trains going thru a tunnel then you could put staging in another room to hold all your equipment and have the room you have planned all for scenery and industries...