What is the recommended R-value to use?

We were using a 4th (not on your list) but I cannot recommend them. 

I would recommend having a conversation with your tenants and letting them know of your interest in selling the property to gauge their interest in terminating their lease early - or if you have a termination clause, invoke it. 

I'm not sure that I would recommend switching them in and out of your name. 

We really took the bull by the horns on this one and patched our way through 😅 but I would LOVE some recommendations for a Tax Specialist, lender, and other important people throughout this journey!

When you go to sell, Montvale requires a certificate of occupancy so this issue has to be resolved in advance of a sale.Although I am not a lender, I assume you will not be approved for an owner-occupied mortgage on 5-units if it is a legal 4-unit without some type of mortgage fraud whether in reported rents, units, or another legal document or representation (very very large issue from a legal perspective with multiple arrests in the last year for anyone playing fast and loose).As far as the DCA, I would recommend coordinating your work with the city with the DCA.

They also have calculators to analyze deals, and I highly recommend you start this as soon as possible, even if you are not ready to buy.

None of which I would recommend. 

If that is a stretch as to your qualifications, I would not recommend this as it would with relative quickness go to the attorneys to move forward with drafting, inspections, title search, etc.

I would recommend finding some local meetups to attend, and also tuning into the Straight Up Chicago Investor's Podcast.