I am currently 96 hours in, and i am experiencing a little lag. I got to thinking about all the arrows laying on the ground from where i miss enemies and i thought that those arrows might add up over time and slow down the game, do they disappear? I sure hope they do, if not bethesda should probably include that in a future patch.

Cells eventually reset.

They do disappear. As stated above cells(areas) reset. Also I believe some arrows disappear instantly. I know some of my arrows that hit disappear so I assume some of my misses do to.

i think its weird that my bound arrows lay around after my bound bow disappears

They start disappearing after some shots.. i mean, try shooting arrows on the floor in fron of you, after like 5-10 shots, the first arrow will disappear, then if you shoot another arrow, the second one will disappear..

And also after a certain time they disappear.

Well good, so is it like every 30 days it resets?