Simplified delayed choice quantum erazer experiment: is it possible to create an interference pattern at D0?

I think there is a basic misunderstanding of the instrumental setup due to the existing double-slit: In the original Young experiment the double slit was illuminated by a coherent light source, producing a interference pattern. In Wheelers delayed choice experiment the double slit is used to illuminate two independent regions of a BBO crystal by the pump laser, each producing by down conversion entangled photon pairs by a pure random process. That means, the "red" photons have no correlation with the "blue" photons. Therefore in your first picture no interference is to see on S0 and S1. In your second picture with the BBO crystal removed you restore the Young configuration with a double slit illuminated with the coherent laser radiation and interference at S0 and S1. In Wheelers experiment interference at D0 occurs due to a selection of a sub-set of all events at D0 by the coincidence counter : Only events with a coincidence (by pure chance) of the "red" and "blue" idler photons (going in downward direction from the BBO crystal) are used. The entanglement of the idler with the signal photons creates at D0 a "synthetic" coherence of "red" and "blue" and thereby interference.