ACI 301, Section 2.3.1.12, Embedded items are NOT to be placed in after the or during the concrete pour. These items must be pre-located and verified for height and X/Y location.
When installing precast planks, we should have the precast contractor plug the ends with mortar, in most cases, to prevent animals and water from getting in the cavities during construction.
Design typically does not take the camber of precast planks into account when designing the floor topping material.
Precast or tilt-up concrete panels will have lateral deflection from wind pressure (positive and negative). The deflection will depend on many design elements, including rebar in the concrete and the length of the panels from connection points.