I was trying to make a bow that creates an arrow every time it was drawn. I choose Adamantine only because it would pass some DR and was a choice with the major creation spell but Adamantine was not a goal.
The part about manyshot was a thought I had with regards to the fact that if the bow is already creating an arrow when I draw it, I could use an arrow from my quiver at the same time. I thought that if it didn't effect the arrow being created magically then it could shot two arrows at once like the manyshot feat but not hinder my attacks per round.
The negatives I attached in my description was an attempt to not have the bow be to powerful.