To conclude, Apartment Syndication requires a list of certain skills, and the above is by no means an exhaustive list. 

Is an intention to hold it one year any different than an intention to hold it 5 years?  

I am just baffled by such posts, how it's anything other than an attention thing. 

While there may be state minimum standards, nothing prevents the community from establishing higher standards.The very fact the home is 20+ years old may, in the community owner's mind, make the home a liability rather than an asset.

The exhaust for the hot water heater is 3 inch instead of 4 inch pipe, the electrical panel is a model that has a recall on it, There is slight seepage at the galvanized water main coming into the basement etc.

Unless you exhausted other options I'd consider pivoting and searching for $$$ else where.  

Our rents average around $15K/month for the duplex (more in summer, less in winter).Where I take big exception is our vacancy rate during the GR was so high we converted one of the units to LTR because doing so was more profitable than an STR that was rented at less than 20%.The other big risk of STR is STR regulations.

I had just bid on an old rundown motel in the keys that was 9 very small rooms on a little less than an acre on the ocean side, no onsite concession allowed and huge building permit hurdles, that would have been all in for about 5m. 

Other than an 19 year old furnace and a roof that was on the last third of its life, everything checked out and was functional.

I would expect these two cabins to perform within 5% of each other and for whatever reason it is not and I cannot explain it other than an algorithm change in the OTAs.