Hey Klaus thx for the pointers!
Regarding 1, should I still cut out the parts of the model in the high poly that won’t be seen? Say if I had a ceilling cornice attached to the ceilling where the top and side would never be shown, should I get rid of those faces of leave it on? I believe the model needs to be whole and even contain some meshes inside if its a destructible. But I might be mistaken.