If I had not inherited this tenant with my building purchase he certainly would not have been anyone I would rent to after a background check revealed these things to me.   

Do you think the rest of the letter does enough to establish my sincerity without mentioning education and farming background?

Some guru's do have solid backgrounds as investors, but many are dillussional in believing that their way is better, newer, etc. 

RE simply is not for everyone and that you can go from zero to an investor by learning some techniques etc.. you can learn all of these techniques here on BP or through gurus its all the same material it really is... one is free basically ( here on BP ) the other is paid for.. or you can go the private mentor route ( highly suggested for those WITH Money) and have some business background....

I wouldn't be too tough on background test either, just have a solid contract.

Excuses about late rent have fallen dramatically as credit scores have risen (the previous landlord didn’t do credit reports or background checks)Now more on the second year of ownership.  

If nothing looked funny with the background check and good/ave credit history I may rent to them.

I will be working from home providing live captioning for various events, and my partner has a background in mechanical engineering and aerospace.  

The partnership returned my capital because (1) my finance background and (2) my partner's experience in the field.After watching Shark Tanks and reading investment blogs, I decided it would be a good idea to start thinking for real estate investment.

Also, some inheritance can be given in monthly installments and that may be a problem.The bottom line is, if they have enough money either in their bank account or they receive enough monthly, then they should be fine.Assuming they pass the background check etc.