Costs after it’s placed in service are deductible as rental expenses.If you need help tracking these costs or categorizing them for your tax return, consider working with a tax professional or using software that helps you manage rental property expenses.

Build a strong team, including agents, lenders, and property managers, and use tools like the BiggerPockets calculator to analyze deals.

First things first, when assessing property managers, it is crucial to prioritize their ability to collect rent and manage delinquencies.

I say that because every decent legit place I know of in market, yes offers the option of doing just tenant placement, for self-managing. 

Staying involved in a business partnership while dissolving the marriage will rarely work.If you split the properties, I recommend hiring a good property manager.

Is it Leasing, Property Management, Vendor Management, Operations, Finance, Accounting... 

The only other options I can see are A) your mom partnering with you rather then selling the property to you - you become 50% owner and bring the funds and management to the rental while she provides the existing equity as her contribution; or B) your mom lending you the rehab cash out of her personal funds while also seller financing the house to you. 

I am also a project manager and a architectural designer for a real estate developer in NYC. 

Start as a co-host and work under a vacation rental management company in the area to learn the ropes.

Oh man- welcome to self management.