is there a place where i can store all my stuff or i can just throw them to the ground at the main fountain and they wont dissapear?

They shouldn't disappear, hasn't happened to me except once when I dropped a bow I planned on leaving on the ground but it disappeared so I reloaded and then dropped and it was there so it could happen I guess.

However, it may add to the current memory leak and certainly makes the game run slower if you leave too many items on screen so try to spread them out (preferably in chests, cellars or upper floors to avoid it when you enter a town.

I wonder if there is a console script to delete all items/bodies on the current map? That would be a use at your own risk tool.. but if you were sure that there was nothing left on the map you wanted it would be nice to do a purge. Sometimes it gets a little crazy when you end up grinding in one spot for a while... just a little messy.