The second floor has 3 bedrooms and 1 bath.My plan would be to convert the garage and living area on the ground floor into additional bedrooms to make 6 rentable rooms ($6k per month total revenue) with shared kitchen.

And in addition to it working for us personally it also seemed to make sense financially.

Thank you for taking the time to offer your insights.

Ask one additional question you "forgot" to ask at the meeting.Scan and toss any relevant business cards you picked up.Never feel pressured at these meetings.

In addition, ADUs often add less value than they cost.

It is true that you may miss out on this home, if sold this week, but also consider the Joy Of Missing Out (JOMO) by not overpaying for this property and also footing the bill for many of the potential repairs required for a 120+ year old home as mentioned above by the previous commentors.I would encourage you to take a contractor with you to the open house or someone with experience in this age of home to give you some insight into the property and what may need to be addressed in the first few years of ownership. 

As I inch closer to 60 I find that owning my time is more important to me than any additional cash. 

Most of the investors I work with are pulling every bit of capital they can out of their current portfolio and purchasing additional properties. $800k can go a very very long way, depending on what you want to do with it and what market you are working in.

The interest payments will be additional deductions/expenses. 

just some things to think about.in addition to the BP family of podcasts, the rental income podcast with Dan Lane is a great podcast and he interviews a lot of medium size landlords who aren't flashy but really know what they're doing.