I offer an online payment portal to submit rent payments via ACH or CC - they "couldn't figure out how to use it" so I set us up to accept Zelle payments.

You can also check their reviews online at Google, Facebook, or Yelp.

My recommendation would be to get approved as a Landlord, contact the director's office and request that an inspection be completed before a tenant is selected (sometimes they will do this as long as you select a tenant within 14 days - which you want anyways), and have an online application and screening resource in place.  

There is a cumbersome way to do it on paper forms, but you should not.The only sensible way is to submit your 1099s to the IRS online, however not directly with the IRS.

I do SMS, cold call, mail, online, wholesalers, etc.

Networking, local meetups, door knocking, mailers, wholesalers, online forums specific to your area of interest.  

I’d love to hear about the crime rates or any other issues (which we cannot guess from the online stats), and how easy or hard it is to find reliable tenants and property management companies.

Quote from @Zach Howard: Quote from @Jonathan Greene: If you are looking at properties in the US only on Zillow, and not seeing them in person (I know you are in Hong Kong), this is just an effort in futility because you can't underwrite single-family or small multifamily deals only online.

you can find all the info online"...it's like, no sh*t you can...all the information ever is online!

I have been reading the online resources about getting started, searching the market, and even doing tours, but I am hesitant to jump in and buy a house as I have quite a large amount of student debt.