But I also recommend talking to two Realtors about selling, and they should heavily discount their side of the listing fee if you're going to have them help you buy the next home.

This whole situation relies heavily on personal judgement. 

He's having trouble keeping up with the land lord duties and has been leaning heavily on his daughter to help him.  

This makes more sense to us than relying strictly on  rigid yes or no criteria where any negative  disqualifies a candidate entirely.Some criteria is weighted more heavily and can overcome negatives. 

Also remember that HOA fees will never go down and the quality of the HOA can heavily impact your property value.

While I make a good income, grad school loans have hurt my debt to income ratio, which has made me heavily reliant on partnerships, which have not worked thus far. 

We are heavily invested in this project, from other property sales, thus not the Finance interest weight on this project. 

(every house in the development is situated on 1+ acre lots in the heavily wooded area; it's not quite clear where the property border goes).

The realtors that are heavily involved in RE investment attempt to snatch up the best deals for themselves and pass off the thin deals to other, including you.

So I'd still focus most heavily on looking for a distressed situation when buying, and not counting on an improving bottom line helping you out.