Also verify the existence or placement of adequate property insurance and get named as an additional insured on the property insurance policy. 

Larger multi family units are selling at historically high prices for Oklahoma (as Rhett indicated) so it's tough to find adequate return in those segments right now.

You can manage a fairly large number of rentals part time and use property managers if you have to.If you don't have adequate capital to invest I don't think borrowing money is the way to release stress.

IMO for most people a 401 K is a adequate choice.  

To alleviate any hardship, give adequate grace period for tenant to achieve new rents, it will be set up in increments.

Is that adequate?

Just buy in the right market, have adequate reserves, and make sure the numbers make sense.You have the right thought.

If the tenant had their friend bubba fix something and gave the landlord an over inflated bill then the judge might toss that and award damages to the landlord because the tenant did not give the landlord adequate time to have their repair people look at and fix the problem.Some states are founded on different laws and thus some are landlord friendly and some tenant friendly.

If your retirement utterly depends on having adequate cash flow from your properties, any downturns will cripple you.

I understand preparing for disasters and I feel I am adequately prepared for any minor (likely) problems.