I've read through most of the thread, and here's my solution to the Loader being OP.

Use the loader explicitly as a "Loader", as in it can only take things from a belt, and run them into a chest, or a automated factory. The loader would no longer be used to empty a chest, or have anything dropped ...

I think an over head inserter would be great.

For instance, this inserter would sit over top of a belt, and insert an item on the right side of the belt to the right, and an item on the left to the left, or you can swap the left to pass to the left side of the belt, and the right to the right of ...