-contacting several LP's nationally that take on large investment opportunities-posting on loopnet-sending the link to the website we built-out to all the the top real estate agents in our local market.I did not think of the Facebook group channel, so thanks for that recommendation @Ryan Arth!

With that being said, in a worst case scenario, you can always hire a property management company to handle the day to day items if it comes to that. 

At the end i will add a list of items why adding a single ADU in single family zoned areas may not be the best RE option.The most common value add is via a rehab.  

Taking real time notes on deficiencies allows for clear understanding if the items make their way to a buyer repair addendum.

The AP has to be open, notorious and hostile...those terms have a legal meaning and essentially it is that you as the owner have been fully deprived of your right to the property.Absent those items above, it sounds like at best they have another legal right which is a "prescriptive easement".

Due to item 1, adding an ADU can require years to start achieving any return (once the accumulated cash flow recovers the initial negative position).4) Adding an ADU is a slow process.

If there are items of value left behind, or even personal items of sentimental value, I will follow the abandonment rules to a "T" to avoid any legal issues.

As expenses fluctuate (property taxes, insurance, maintenance items, etc), the cash flow will be up and down and unreliable.

$540 is not unreasonable for a home of that size and the items you mention.

The list goes on.For mission-critical items, you want quality, not cheap.