It's normal to get online inquiries, but I would pay more attention to how many people are physically touring the property/applying.

PHYSICALLY VISIT YOUR COUNTY "REGISTER OF DEEDS" OFFICE:  That's what they call it in TN. 

I know most banks are FDIC insured, but who knows how that whole process would go if it becomes necessary.Therefore, when these guys are saying they have cash ready, do they mean actual physical US dollars, cash in banks (like most Americans), or some other form of asset?

Then I had the thought that if we just went with simple keypads (programmed only on site, we keep the backup physical key), we could require/help each tenant set their own code at move in.  

Physically look at the software they use and ask them how they are screening, verifying when properties are ready for the investor and how they communicate.Once youre good with that and you’ve got one under your belt, then let todays technology help you make more purchases...

Also, what do people recommend for the physical letters?

Any ideas that don't require my physical presence?

I typically send the video to the prospective tenant and have them fill out an application prior to a physical showing.

@Michael Glaspie We typically have 30 days financial due diligence and 15 days physical due diligence.

My leases all say check physically in the UPS box on the first, but if the tenant wants too I'll give em the deposit slips.