With the flexibility of evicting non-paying tenants returning as a card to play, I would assume that the risk of having tenants lessens, thus increasing the demand for rental units. 

How much weight do you put on experience related to property rentals?

Anything 5+ units uses the income approach and not the comparable sales approach for weighting of the value of a property.

Before you take step 2 do a gut check, pray, maybe talk it over with someone who's opinion you will give weight to in this situation.

Get a professional project manager, build a reliable team and get proper education of the market you're investing on.The risk will be there but you'd be able to lessen it.

She does not have that weight, but I do. 

This my general feeling....When you structure things correctly and things are going smoothly, paying  a PM 8-10% per month for essentially taking the rent payment, PLUS one month rent at turnovers is a HUGE waste of $$.When the sh*t hits the fan and things go badly or need a lot of attention, then a PM is worth their weight in gold IF you as a LL can't deal with it......I've only been doing this for 6 years now and only have 3 units and I have self managed them EASILY over that time frame..... nothing has come up that I cant easily handle myself with very little time involved.

I explored this and quickly realized the capital required and the TIME required made the risk out weight the benefit.  

Is it recommended to carpet the second floor of a duplex to try to lessen the noise? 

Keep in mind that the recent sale's cap rates were probably underwritten incorrectly and that those investors have a different weighting for their equity, which will distort the analysis some.