Most tenants are happy to pay it because they understand a broken contract comes with penalties.My agreement requires them to participate in showings to potential renters during their final 30 days.

No, in fact, in texas, a sellers disclosure is not required to be given for residential multifamilies  

However, in appreciated markets, it requires a higher downpayment to cash flow.

Lenders do not require earthquake insurance, at least not in California.

All of these things would require you to see all of his financials on the property and then be able to calculate it all out.  

Others zones that to allow multiple apartments mayhave other requirements such as larger lot sizes, parking, etc. 3.

They might be able to shed light on the particular requirements and factors that apply to homes in your area.Make sure the insurance coverage limitations adhere to the conditions outlined in your FHA loan.

However, I'm unsure how to ensure that the homes meet cleaning requirements when I can't personally inspect them.

I agree with the other responses- lending isn't a great place to start- it's complicated, risky and requires deep market knowledge to not be taken advantage of. 

They do tend to require more time managing and ensuring that your rental rates are competitive based on current STR availability/rates in your area.