We will be looking for a property near by with a residential house as well as a heated shop of around 1000-2000sqft on the same property.  

Getting involved with a partner definitely seems like a smart move for me.

I think that is very smart.

I stocked up and went on a shopping spree.

you don't have one, hence, your gfi's could not be hooked up correctly. i agree, the $15k sounds a bit steep for the total rewiring job. i would shop around for the best deal you can find, but i would definitely do it. yes, of course it would " pass inspection" as is, if a home inspection was about pass or fail, but it's not about pass or fail. its about the condition of your home at the present time. and at this present time, the wiring is working as designed. is it safe???

Assuming the rents cover your expenses, in 30 years when you're in your early 50s and the mortgage is paid off, and you've done the smart thing by raising the rents over the years (this is Chicago we're talking about, not Podunk, Iowa), you will be sitting on a multi-million-dollar asset that cash flows thousands of dollars per month at the cost of a measly $20k or so out-of-pocket when you were 23.

The Real Estate Center at Texas A&M (just Google it) is one stop shopping.

Some investors will have additional overlays, others will just have garbage rates. 580 is as low as I've seen anyone willing to go, and that's FHA/VA only.To be honest, this isn't one where your client is going to have a significant opportunity to shop rates.

The property has two buildings, an office building as well as a shop that the owner uses for his business.

Let me know if you ever want to grab a beer/coffee and talk shop!