AO or Ceramic bead are the best for the product looking better longer. 

I have long time tenants I inherited when I bought a particular property a few years ao.

Fwiw, a 50-gallon electric heater (ao smith or bradford white) costs ~$200 -ish at the supply house in Phoenix, so he's charging you retail.

If the house had any other AO's before you, there might have been a previous inspection done in which it was disclosed to the seller, and you'd have better chance at recourse.The real answer is if this is something you want to pursue, talk to a lawyer.

Then it turned out the property is in AO flood zone, which would cost another $100/month for flood insurance on top of the $110/month home insurance.

The Seller has not put any rental listing yet and I don't think he is planning to.Is there any way I can put a contingency in AOS that the Seller has to find a reliable Tenant (Credit score > 650, Clean Background and Income > 3 times the rent) with a signed lease (market rent), 2 weeks before the Closing else the Seller will provide Seller assist equivalent to twice the market rent?

No one would lend, not even with the signed AOS and 300k down…It was insane, would have broke had Covid not doubled the cost of rent for my rentals.

I put a AO Smith 50 gal gas water heater in my own house (attic), but I couldn't have done that on my rentals as the cities require a licensed plumber to pull the permit unless you're the homeowner/resident. 

I think another 4-5 months will be a great time to jump.Think about the likely scenario - most buyers scared away by the terrible interest rates and sellers sitting on a house through the winter with inflation and recession raging around us.....Just stay out of my AO.

It is up to us individually to improve our own financial education.Depending upon how one uses your 401(k) plan it could be really beneficial (what I mean by this is maximizing the $52,0000/year self employed individual 401(k) and buy discounted notes with the money) and lower your taxable income, or it could just be a savings plan that makes the institutional account holders rich that distribute your income among various mutual funds.For those seriously interested, I highly suggest reading the book '401(k)aos' by Andy Tanner.