Also, access to online HMLs is compressing the total returns as the market gets more efficient.

Maybe with automatic payment stuff and you can request changes to your credit card due dates, you can take as much advantage of the float. 

I have renovated 13 of the 16 units to date and have raised rents closer to market rent.

You might also consider talking to the tenant about shifting the rent due date to the first of the month to avoid future confusion and align with typical forward-paying leases.

I’ve come across options like the Institute of Real Estate Management (IREM), National Association of Residential Property Managers (NARPM), and Certified Property Manager (CPM) programs, but I’d love to hear opinions on which have been the most valuable in practice.Additionally, any recommendations for resources, books, tools, or online communities that have been helpful for day-to-day management would be appreciated!

Banks often have higher fees and less favorable rates, while online services like Wise offer more competitive options.As @Ryan Konen mentioned, other alternatives include Revolut for multi-currency transfers and OFX for large transfers without limits.

Ive also heard of online marketing campaigns--targeted FB ads--that can be configured to only target users on your marketing list.

Here are some numbers: Current PITI: $3,970Estimated rent: $4500-$5000 (there are several homes within 4 blocks of mine that owners have turned into rentals and I've been able to compare online pics to our home, so I am confident this is a good estimate)Sq ft: 1790Estimated sale price today: 1150000-1250000Mortgage balance: 612,000I would self manage. 

He is easily accessible if you find him online and he is a great guy.

All the military units have websites, so you can look them up online and call using the number you find there.