From my research, I'm seeing $100-$150/sqft depending on complexity and material.

Adding this circuit in would likely be quite expensive depending on access between the laundry area and the panel.

Depending on what he is offering you i searched the address with the secretary of state. 

Going to depend much more on more details / your personal situation - all things equal you will probably get better rate/terms on conventional if you qualify for both

As far as being expensive; if the tax liability is not large enough then yes I agree, however, it depends on what is being sold too.

It depends on what the terms of your mortgage are.Pros-with no mortgage, you have higher cash flow.Cons-if you plan on buying more properties, you are better off saving the money for a down payment for your next place.The big questions are: can you get higher than 7% return if you invest that money elsewhere? 

In our experience, things move in ebbs and flows and the speed of rental depends on your asking rents relative to competition.For example, there was a period of several months at one of our properties when a 3 or 4 BR unit came on the market it rented almost instantly. 

The market is always evolving and there may be good deals to be had near term or you may need to wait a while, depending on many factors like interest rates etc.

But the likelihood of success with that depends on the specific street.

Unfortunately with those numbers it's tough to find a non-bank lender/financial institution that will lend.Usually loan minimums are $50K and the up to 75% LTV on purchase-money/70% LTV on cash-out refinancing, which basically means you need up 25-30% depending on the type of financing.