For your first question, writing a scope of work (SOW) involves detailing all the tasks and materials needed for your project.

In that case you should get an attorney involved as encroachment would be a material issue that if known should have been disclosed both to the broker and to any potential buyer.  

My bank connection breaks multiple times a year, and we are going on 2 months with no offered solution from Stessa other than they are working on it. 

For example, if you're planning a kitchen remodel, get multiple quotes to ensure you have a solid grasp of what it will actually cost.3.

You can often get better rates with a national lender, but the customer service is non-existent, communication probably sucks, they may ask for the same documents multiple times, etc.

It's much easier to set things up right than to have to transition them later when you have multiple properties and many, many transactions.

When you add that: "The downpayment and closing costs would be one large hurdle"; I can't tell if you can only afford to do this once (thus tying up whatever you have saved) or multiple times.  

Most people cant afford that alone which means a syndicate or getting PMLs involved and doing the synd yourself. there's nothing wrong with starting with some smaller properties.

Leverage magnifies return. 3) The effort involved in adding an ADU is comparable or larger than a rehab associated with a BRRRR.

Shouldn’t it be at a lower multiple?”