A) Combination of UA + Intra-EU LH, so not a risk of flights being cut complely
B) cash, otherwise P/PZ wouldn't matter
C) Yes

But these are not really relevant. I was mainly looking at in principle, as I see 2 possibilities for any itinerary to anywhere in Europe for me at this point:
1. Book now to take advantage of P/PZ - disadvantage: schedule change hacking up the itinerary, having to reroute
2. Wait for the schedule change to get a more stable itinerary, somewhat less likely (though anything can happen) to get schedule changes - disadvantage: P/PZ gone, tickets becoming more expensive for the same itinerary for the same day.