This doesn't work with a portfolio of a couple; I wouldn't try this on less than 20 or 30 capital equal positions with either a 50% long stock and 50% short stock in a trendless market or 66% vs. 34% long or short stock in a trending market.
Very safe consistent gains with a few problem...
See all of the above answers; I think I have just answered all your questions except it is not a vertical and the short option is ITM or ATM.
We don't normally trade against it ...
Works off of the disparity in a rich short option against a cheap long option; i.e. long stock, short ITM or ATM call, long OTM put or short stock, short ITM or ATM put, long OTM call.
1 to 5% per month on a diversified prtfolio of equities.
Never tried it on bonds.
Never tried it on futures.
Scan for 5 to 10% monthly yield on the short call less the long put cost.