If, however, there are any gaps at all in any of the above items, even a gap so small a mouse can squeeze through, that tenant will exploit it and your life just became a 7th Level of Dante's Inferno.....:)

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. 

That's it, but a) print out a page for each property you think is comparable, b) make the list of repairs long and inclusive of everything you've done. c) Put larger items first like kitchen remodel......and don't just say 'kitchen remodel', list things like 'custom backsplash tile/Bosch appliances/recessed can lighting/pot filler/etc. d) Cite the price/value of the work done, and don't be afraid to be generous.

But enough to make to do all the cosmetics along with a few major items like HVAC, appliances, etc.

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.

Unless you are itemizing your tax return, the interest on the primary is not tax deductible.

It would cash flow nicely.One item to plan for from the beginning is the exit. 

It’s ran like a business, not a personal investment.Given the heavy workload I have being the CEO/founder of the wealth management company, my wife has set up a well oiled machine on the property management side, due to her perfectionist drive however, it still means that she's constantly dealing with tenants and toilets and replying to items at all hours of the day and night.

An example of a mistake was a line item for alimony that I found on my taxes (I am single and have never been married).

How much can you budget for furnishings and all kitchen items and creature comforts for the ones you want to MTR.If you have a vacant 6-unit, you have great possibilities to try all strategies.