However, the law requires me to find a replacement renter was quickly as possible and minimize the financial impact to the tenant.

Managing the $35,000 renovation budget required careful oversight to ensure timely completion.

Having the money to spend while also leaving it to the next generation is going to be tough.If she's got her heart set on real estate, get her a solid rental where she can spend the rental income and when she's gone, the heirs can sell the house and do what they want with that money.My mom (early 80s) just sold her house and bought a less expensive one-she put her left over money from the sale into a bank account with high interest.  

Will this require the septic tank to be replaced with a larger one to meet code?

I also have a local bookkeeper, QBO, Bill.com & generate owner statements in OwnerRez.We currently have 23 properties under management and am utilizing trust accounting to the best of my abilities (although we are not required to in our state) but everything is really inefficient when it comes time to do monthly reconciliation and distributions.

$18.14 First Alert Plug in carbon monoxide detector - https://www.amazon.com/First-Alert-CO605-Monoxide-Detector/d...Most jurisdictions require CO detectors.

My main goal is to house hack and make my monthly expenses as low as possible.

I’m Not even sure this lady can sell it down the road with these restrictions in place, assuming another person doesn’t force her out in 3 years.I was just seeking ideas for a course of action that doesn’t require hiring a lawyer as the first step.  

Require him to smoke outside, at least 10-15 feet away from any of the neighbor's doors or windows.

You might do some value-add type rehab, raise rents, reduce expenses by upgrading systems, appealing assessments, shopping insurances, etc.If you can find a deal now and you work that deal, it should on average get better over time ESPECIALLY when you get that opportunity to refinance at a lower rate.