The parliament doesn't get to choose the laws it has to vote. The parliament can't repell a law, and doesn't hold the pen during negociations.
This isn't exactly true. They can't propose but they can amend. The final text has to be agreed by the commission, the lower chamber (the parliament) and the higher chamber (the council, which is heads of states).
So the laws that Parliament votes on just appear in session magically? They're not written by EU citizens and politicians?