You asked about buying older properties and the biggest issues I have found is that roofs need to be replaced, HVAC needs servicing/replaced, and sometimes there are foundational issues (not super common). 

In your experience do you see people commonly attempting to offset ordinary income / W2 with syndicated losses, despite the above?

So this is common thought and why it is a real challenge to get debt secured by the ADU value add at higher than 50% of the addition cost. 

"Is it a common practice to report it as a loss even though I fixed it out of my own pocket?" 

With four plex you have to pay utilities for the hallway and common areas, also maintain and clean the common areas, because the tenants won''t.

I am putting it up on Facebook, Craigslist, etc. but is there anything else a newbie can utilize that you have found success with?

Trying to manage a $1M Airbnb rental while it sounds good you got $6500 in bookings you still have significant costs to operate it with maintenance repairs, utilities etc.

It's common for traveling medical professionals to extend their contracts.

I spent 2.5 years getting all the utilities to the property.

This explains why your taxable income was zeroed out on Form 1040, even if the standard deduction wasn’t utilized.