Its a matter of wiring tracing, but these are some serious mains, albeit residential, that you unless you are comfortable and sufficiently skilled, you shouldn't be taking the electrical panel covers off to see how things are wired... 

We were looking for a value add deal where we could utilize our construction experience to rehabilitate the property and we were looking for a smaller older home with a large backyard sufficient enough to build an ADU.

There is a vast variety of homes you can invest in from under $100k with great a great return to expensive luxury homes you might be able to flip and get a good deal.

To a PM, you will be viewed as low profit, high maintenance, and high liability, and it's very unlikely they will have sufficient incentive to solve this problem for you (even if they have the experience to solve it--which they may not).Even if you could magically find a PM who is experienced enough, and motivated enough to solve your problem for you, you need to take responsibility for this situation, take a role in solving this problem, and learn from it so that it never happens again. 

I mean if it is like a 2b property, 2 parking spots may be sufficient?

If you purchase at 96.5% ltv, you need to get the value up sufficiently so that the loan amount is 80% or less of the new value of the property. 

We have a sufficient amount of security deposit, so I am considering charging them the remainder of it's useful life (+/- 90%) based on 20 years, purchasing a new one, and offering them the old one if they wish to haul it away at their cost.

That would definitely be an awesome price in the vast majority of markets.

Is email notification sufficient or do I need to post it on their door?

This should be sufficient to cover the expenses of the property (including vacancy and capex reserves!)