I am familiar with the 1% rent rule which would imply that I should be looking to get around 3500-4500/ month for a house in this price range.  

There are times to use monthly MI as well if you think you've found a great deal where you can force equity or improve the value of the property so much so that your current loan with monthly MI will be at 80% or lower LTV/loan to value after your improvements then monthly MI is better because you may end up refinancing or removing MI 6-24 months after closing.

Do I go with the 2% rule on rents I hear all over BP or the 0.8% rule on rents from The Millionaire Real Estate Investor by Gary Keller?  

I agree with some of your concerns, but if you structure your lease term from August-June, you could mitigate the vacancy and still receive rent for 11/12 months, with one month to turnover the rental and complete any improvements that are needed.

When acquiring these old gems, or objective is to improve their energy efficiency by a minimum of 50% (40% on newer, post War houses) while updating the building to provide modern, healthy living spaces for our tenants.  

I started with Wells Fargo as they are my primary bank and I have a good relationship with them.Is there a general rule of thumb for interest rate offered by banks, big or small?

Do these number Monthly Gross Rents $ 4200Monthly Expenses  Vacancy       $ 336 (8%);  (including here since 50% rule includes vacancy as part of expense)  Prop Mgmt   $420 (10% of gross rents)  Insurance     $208 ($2500 yearly; quoted by insurance agent)  Prop Taxes   $680 (2.9%/year of assessed value; actuals; eats up 15% of gross rents)  HOA fees      $330   Maint Reserves:   $420 (10% of gross rents)  Maint/Repairs       $84 (5% of gross rents)Total Expenses : $2478 (59% of gross rents)  NOI:   $1722  Mortgage: $1215 (25% down @ 5% interest)Approx Cash Flow: $507/month (about $125/unit)Cash-on-Cash: 7.2% (Assumes 25% down + 3% closing costs as initial cash requirement)Thanks,Jacob  

@John McAuleySpecifically, the transaction you mentioned would be in violation of the following prohibited transaction rule."

My end goal is I want to rule the freaking world if I can.

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