I've applied for a conventional loan: 3 units, owner occupied, NJ, 5% down.I have enough W2 income to cover the loan and additionally, there are two units rented already. 

Do I add it to my cashflow, or put it into a separate account?

Meaning, after the home was fixed you could be looking at an additional 2 years of rental before it would qualify under section 1031.

Additionally, investors can hire a property manager to handle day-to-day operations, freeing up their time and allowing for truly passive income.2.Real Estate Investment Trusts (REITs)REITs are a passive investment option that allows investors to purchase shares in a company that owns and manages a portfolio of income-producing real estate properties.

if you need additional advice or further help, feel free to message me. 

Adding her to the current lease and charging for the additional pet rent?

There is a cabin on the property that can accommodate additional 6-10 guests but the current owner has chosen not to rent this cabin despite the numerous requests.

For me I use 6 months of reserves (monthly payment mortgage, property taxes and insurance) for each unit (if a duplex it's 2 units) and an additional $10,000.

In addition to that I love accounting and tax and love helping people and pointing them in the right direction even if our model isn't a fit for them hit me up any time!

Sounds like its a $4k tax planning fee and then they do your taxes as well for an additional fee.