I've been fortunate enough to work with a few different property managers, but mostly people my family chose to work with.

Events like this give the opportunity to meet and talk to investors from all over the country, doing different kind of investing, and with a varied amount of experience.

A great alternative would be simply licensing or leveraging a different web forum platform that already has a mature mobile app available for and that BiggerPockets could simply redirect mobile users to when they open the site.

I considered sound proofing the ceiling of the unit below but I’m reading articles saying that it can be very pricey and it won’t make a major difference.

It's just a different mindset. 

I won't go into a lot of detail here, but I was forced to foreclose on three properties in Baltimore with three different borrowers. 

Why can't I go into whole foods and steal their food without getting the police called on me?

I don't feel there is one answer to this question as every property is different and what are your goals, how much time do you have to manage, what are your strengths when it comes to working the trades, people skills, etc as that will help drive towards your super power. 

As you look at different RE approaches then figure out how you will Scale to the size you need.  

The text specifically states the end of three years with about $174,000 and a 348 percent return but the table in the text shows a different number.