These properties tend to hold value better and offer stronger appreciation compared to duplexes or small multifamily units.

However, i'll likely be looking at additional ways down the road to be even more secure for a backup what if scenario.  

That is often a matter of opinion and will depend on the attitude of your municipality.Most municipalities do not require neighborhood approval, but will offer the public opportunities to provide input which will be considered.

They offer a $10K repair fund to fix damages in addition to SD plus warranty for appliance repair etc.I have no say in whom they choose to move in, whether there are animals, limit on # of occupants etc. they reserve right to inspect property so i have no idea if they can tell me to remodel, paint etc.does this make sense i have a vacancy coming up in October (bad rental timing).

It likely is out of date as to cost as this info is quite old (my guess is 5 years but it could be longer):- Rent Recovery Service: offers flat fee service starting at $20. 3 letters start at $30.

Duplex have different zoning that may permit additional units.

I just talked to two banks and they both said that they don't offer them for investment properties.

I've been surprised at properties that have passed conventional financing though...and even FHA....also, one could present 2 offers to seller--one for a cash offer and one for seller financing (at a higher price of course). 

The Main St property in Grainfield, KS, offered a promising opportunity due to its low purchase price and strong potential for a high return after renovations.

Diversifying geographically can also reduce risk and increase long-term returns.For example, there are several markets across the U.S. that are ideal for new investors because they offer affordable entry points, reliable cash flow, and strong economic fundamentals.