Or, if it is treated as a balloon, taxes are due when balloon is paid. 

Sometimes sellers are very structured, controlled, and follow the rules to the letter, but sometimes they may not be as smart.

Once you decide in a buy box and show them a financing letter from your bank.  

This whole thing could go south real fast, send another certified letter giving 3 days to pay July's rent.

After reading the letter I received from the town we determined that according to their criteria I did not in fact need the permit.

Should I have the agent send three separate offers, or is it more effective to choose one offer and include a letter that outlines the other options?

The interest-only balloon of 3 years with a buyer option to extend for 2+ years will give you time to secure permanent financing.

Just last week we got our preapproval letter from The One Brokerage.

When I go through a closing I make the seller return all security deposits to current tenants prior to closing then have the sellers attorney give me a letter that states they were returned. 

The lease document clearly says Amount due at Signing in bold letters.