Sounds like you want a AC game in fantasy setting more so than a TES game. You might have a better chance to suggest that idea to AC board after they run out of historical era to trash. Or, maybe what you really want is a sandbox Dishonored, but at any rate, the idea you described have a far fatter chance to be realized in a none TES game than it would. Physics is wacked, for sure, but if each object have weight, material, physics applied to... Good luck running it with current hard wares. For example, even most phyx engine enabled game has a handful of gimicks, i.e. window shattering, paper flying, and even with just a few objects it will take a performance hit (3-5 FPS in Batman:AC on a top rig) imagine now you want it on everything... And how real are you going for ? Objects effects by wind ? Fireball spell decrease in size with lower air pressure ? Lightning spell fizzle when moisture in air achieve certain point ? Weight changes depends on object is wet or not ? Not only would it be taxing for the system it would also be taxing for 'entertaining values'. Imagine a Hollywood film without Hollywood magic... I would be happy with object flying around less and live in a world where games are just entertaining. TL:DR Sounds more like you want a sandbox dishonored or a fantasy AC than TES game