[JefferMC]

In the OP, it was not specified the conditions upon R1 when she missed 3B. Was there a force active? If not, why would tagging 3B with the ball consititute an out, i.e. until she touched home there's not offense to appeal; the runner can simply come back and touch the base?

Then, on items B and C, I see a clear case for obstruction. I'm sure there could be an opportunity for USC on C.