re: Can you sell calls to establish a short position?

Calendar bull call credit spread. I think that is what this would be called.

I mentioned this earlier, not a calendar spread, but just a credit spread. That would certainly give him a maximum loss certain, and wouldn't drive his yield down that much. He could sell monthly or weekly calls against the other call in your calendar spread.

But frankly for the 5 contracts of the mini, which SPY essentially is, he should have just bought 5 puts for $500ish, and been done with it.