The challenges are Did you work with any real estate professionals (agents, lenders, etc.) that you'd recommend to others?

My overall goal for my professional career is to start an investment firm and own a big multifamily portfolio and get into development.

You should look into whether you can hire an officer to walk through your problem unit and have his professional opinion on whether they are smoking in the unit or if it is a residual smell.

I think they used to be more helpful in the past and they made some changes and now they're not so valuable.I see weird and different values for my Airbnb stats depending on if I'm using my laptop or phone to view them.

Oh look, you get to deduct your cell phone, your internet, your tax prep, all kinds of other things regular people don’t. 

I use Stessa for accounting, I love it, it links right to my bank account/credit card accounts and I can assign purchases to different properties and units of the property for multi-unit properties and at the end of the year I have a simple report to give my tax professional 

Most of them do not and can even hurt you - as your S-corp with rentals. yeah this was under the guidance of the tax professional i went to.

Please let me know who you have worked with and why you like them (How many properties do they manage for you, how long have you worked with them, what you like about them etc.)When the unit is vacant, do they cover the cost for professional photography to rent it out again, or is that an additional fee? 

Attractive digital marketing fliers, 3d tours, professional tours, rent specials, and competitive pricing all help too!

No matter which path you take in real estate, surrounding yourself with professionals from different fields—contractors, lenders, brokers, investors.