Welcome to w4o. Sorry for the delay in replying.
In MW leaving an item lying around was perfectly safe, but now in Oblivion, combined with RAI, i wouldn't recommend leaving any items lying around in the street. Many NPCs will probably 'tidy' them up or just thieve them.
As for items flying all over the place, i should hope that this will come into affect, and that as far as it being resorted afterwards, i guess thats down to the NPC who lives there. I'm sure its a possibility. The world seems fairly persistent as far as NPC activities go.
Don't quote me on this though

And again, welcome to the boards.