See if you can find this product Plaster in a Roll.
It goes on like wall paper but is plaster based and very strong.
They will also have the required bonding products.
To remove the paint try misting exposed plaster with water mist the wall as often as you can till it wont take anymore water than the next day you should be able to remove a lot of the paint.
May be able to start removing in a couple of hrs.
Keep the exposed edge wet.