I've been trying to get good deals over the last year or so to continue and grow my portfolio and passive income, but the markets I'm looking in have been overheated and good deals are scarce.

My strategy would be to let it cash flow initially for the next couple of years, and then if the area keeps developing, determine if its worth making substantial improvements to raise the rents significantly.There are definitely some risks with this property: many tenants are on short term leases; and there is the risk that the immediate surrounding area does not continue developing as it has over the past couple of years. 

I think you need to decide if you want to turn this into a business or continue doing one offs every other year. 

Remember you will have to maintain the license and do continuing education to keep the license active.

Alternatively, you could continue to hold and rent them out assuming that they are cash flowing well and either do a cash-out refi (preferable for your next buy/hold) or a Heloc (preferable for fix/flip or value add purchase) and utilize some of the equity to increase your holdings.

I’m looking to make the duplex a full rental property and continue my investing journey with it.

They also continue your depreciation schedule.  

Now, I expect to continually grow my income over time, even in retirement, and will be taxed higher than I am today, which ironically, creates a desire to leave my W2 so I can access the 401k balance sooner rather than later.  

Continue to watch your investment grow and repeat the process with larger apartment complexes.

Instead of continuing to build up my real estate portfolio in small multifamily (1 - 4 units),I am now leaning more towards Syndication and possibly Triple Net Lease opportunities.