I'm thinking of asking my RE to stand in.   

I believe the changes will only satisfy your personal not financial goals.If I were to change anything I would either run the front stairs straight up to the 2nd level as opposed to a platform and branch stairs to the sides.

The issue is: where do I find a legal basis/precedent to knock this down before I spend ALL of my retirement fund standing up for this principle in my so-called Golden Years?

Also if you know what it take to repair something then when you own a hundred doors you stand a better chance of not getting ripped off if you choose to pay someone to make the repair.  

Great financial advice as well.

Although our portfolio is growing substantially and we've got solid income coming in, I'm not sure that it's quite at the point where it would stand alone on its own and command financing options (without my wife's W-2 income). 

There are lenders that will base their lending decisions specifically off the rents received, not off your entire financial situation.

My husband and I are looking for a partner (financier) who can help us structure a deal to buy our duplex from our landlord. 

Account Closed I'd say with those 2 books you are ready to move onto next steps which is: networking with investors in  your area, find an investory friendly agent, and start getting your financials into order. 

The kind of thing that doesn't make or break your project financials - ie perhaps the jurisdiction doesn't have a great chance of 'making' you do it, so you can take it on more from a 'bring upside value' to your rents, etc.... and you get some 'soft' experience working through jacking something, pouring 1x new footer for a corner post, etc.