Can you play a card for Event + OPs, and then use the OPs for RP or RD, or do you have to use them for move/attack OPs?
You may not. An RP or RD Action Round is just that - there is no "event" occurring or OPS being spent. You may only play a card for OPS or as an event during an OPS, Event+OPS or Event Action round.
Designer, Shifting Sands