If you are ok with the risk, ARM loans from Busey bank offers loans with a 5 or 7 year fixed rate somewhere around 3.5%.

Do you want to roll the dice with your savings and risk losong it all?

As to what to bid, that's going to depend on your numbers and your risk tolerance. 

Now you have the benefit for you and your IRA your were looking for, just on 2 deals that spreads your risk.

You'll need a builder's risk policy to cover the property during renovation (if you're not occupying the property).

I'm trying to weigh not just the potential savings in dollars but the value of risk mitigation and having him in the loop since he also does my taxes and estate planning. 

The tax deferred nature of appreciation and the long term low-risk history of holding New York property make buy-and-hold at cash flow neutral, or even negative, compelling for investors with other primary sources of taxable income.

It's those maniacs that buy homes cash via quit claim deed off of craigslist that really get screwed.Make sure your property manager is a licensed real estate brokerage.Understand you can not eliminate all risk, only mitigate it.

Yes they will use all units assuming you're not occupying at all.To understand where the SS rule comes from, it is used to reduce FHA's risk in insuring these 3-4 unit mortgages.

I understand where you are trying to go, but what scares me in your scenario is that if something goes wrong in your life (illness, job loss, divorce, etc) you now have your personal house at risk.