After renovating and renting three of the units (while living in the 4th unit), I am wanting to refinance to pull out some equity and lower the interest rate. 

Real estate meetups or online forums can be gold mines for this kind of info.Detailed Inspection: Consider hiring a professional inspector with experience in renovations to give you a detailed rundown of what needs to be done.

Houses come with their own land which condos don't.Condos are less expensive to buy, but you have to also remember there are condo fees that depending on the unit can add to the monthly payment. 

The HOA in which the unit I am purchasing provided their HO-6 policy to our lender and our lender is questioning the following as it appears on the policy:Special FormReplacement Cost (Actual Cash Value on Roofs)The verbiage in parentheses is the one causing the hold and need for clarification.

My broker bought 2units 2 years ago and has $400k in equity already (approx. 300-400k per unit then)

Would it make sense for you to live somewhere else and rent all 3 units to maximize the income on the property to eliminate your debt?

4 units all three beds$575,000All CashRents of $1,800What makes it good for us?

There is a triplex property (4/3 main house, 2 individual units  3/1 unit, and 2/1 unit towards the back of the property) and 3 units sitting on a spacious and buildable  0.71-acre lot.

You need to consider the safety and welfare of your other tenants (if this is a multi-family unit).  

Investment Info:Small multi-family (2-4 units) buy & hold investment in Minneapolis.