Curios why you didn't have the loft over the driving area, as so many Class B and C RVs do. You never need to stand up in the driving compartment anyway, so it leaves areas where you might want to stand up free.
Either way, the removable panel is a good idea. My camper van had one that slid on top of the fixed panel, so you didn't have to take it down or find a place to keep it, just prop up the edge and slide it down between the mattress and the fixed part. It was about the same length as the fixed part, so it cut the sleeping area in half.
Also, I notice a lack of sofa or chairs, whats the plan for that?