(Presuming you can), and taking out a loan on a personal property you could live in (you’ll get a lower interest rate that way -although still a high one), and then down the line refi it when the rates get better.  

Where I am at It is 8k For all new electrical, 8-9k for central AC (assuming no existing duct work ), Not too sure about plumbing because my contractor owed me a favor so he did it free, however he did replace all of the plumbing, Flooring 2/sq ft (labor only), Got both bathrooms done for about 8k including materials, the roof should be about 10-15k Obviously its different for each market  but for a presumably smaller duplex, 90k seems like a lot.

But I thought for sure a sanitation worker would have no such issues.I figure these guys are a better source of vacant and ugly houses than anyone because they presumably cover more ground than letter carriers (visiting a neighborhood once or twice a week instead of six times, ergo more neighborhoods per week?).

I figure a solid 10 hours work at a minimum for a turnover, maybe as much as 20.If you're living in one of the units, that slightly reduces your expenses (I presume you won't wreck the place :-)), but it takes away a chunk of your rent.I don't give you then numbers to discourage you, but to help you understand the reality.

I presume the lender is hands-off with the DOT or promissory note as this is outside the scope of their purview.

What notice do I need to give here and what is the best way to avoid conflict (I presume she is not going to be happy about the notice).

Presuming they can afford it, and the rent is close to the market, a modest increase in rent isn't likely to cause someone to move.

@Amaf J.Since all FHA mortgages require that you owner occupy one of the 4 units, presumably your contribution for the negative cash flow would be a rent in lieu payment. 

also I presume I will need an architect?

In that case it would be presumable that the condos are a part of the condo project with their own set of deeds and the land is a separate deed as well.