You can develop a system based on one metro area.I'd think the purpose would be to better describe a property, it will take a broad brush to paint an accurate picture and compare a parcel in Toledo with a standardized ruler so that someone in Chicago can relate to that property without knowing the Toledo market.

Jesus once told the high-affluent ruler to get rid of his infirmacy by dipping in the Jordan river seven times.

Does not meet the 1% rule, rent at least 1% of sales price 196k.

The ruler of Iran actually said that.

I am way over the 2 percent rule, really approaching 2.5 percent.  

There is no set rule r time to hold, however, 12 months is typically the minimum but again, the intent is the key for the IRS. 

In a market like southern California where the cap rates are for the most part under 5% it has been very difficult for me to find any type of MF property that meets the 1% rule (rents being at least 1% of purchase price).Should I just keep looking until I find the needle in the haystack or are there other criteria that is more important when trying to invest in a cash flowing buy and hold investment property? 

But applying the 50% rule will serve new investors FAR, FAR better than the phony cash flow lie.If an investor applies that rule, realizes they will have negative cash flow and chooses to invest anyway for purposes of speculation (which is in part what you're advocating, and is a perfectly acceptable strategy) then I have zero problem with them. 

After filling it up they put the ruler in, and if there are no leaks the water level stays the same. if there is a leak the water level drops.

Since the market sets the rent and not you, that rule really means you have to pay no more than 50X the monthly rent.