My hope being that the other units would be a wreck and that I could beat that price down instead of pulling out. 

My goal is to not get wrecked on this first deal, have a decent cash flowing park, and begin the process of accumulating enough cash and equity to get into a bigger one.

I figure a solid 10 hours work at a minimum for a turnover, maybe as much as 20.If you're living in one of the units, that slightly reduces your expenses (I presume you won't wreck the place :-)), but it takes away a chunk of your rent.I don't give you then numbers to discourage you, but to help you understand the reality.

Tell squatter the judgement will wreck his credit.

I sure hope they get out without wrecking the place ASAP!

If things go south with the fiance before the house is complete it could really be a train wreck. 

Some of these include the high likelihood the homes are used as party houses, they are often in single family neighborhoods and wreck havoc in those neighborhoods when poorly managed (common).

Your not going to wreck your own place or have to be evicted.

As Mike M stated, it can really be a mess and wreck relationships etc.

The owners are still living in the properties, so the homes homes aren't a "wreck" inside.