@Rich Beam I have a couple of laundromats of different sizes.

Since I don't know anything about your stepmom's estate, it's size, her objectives, you can check with an estate attorney about "irrevocable trusts" where you'll be the beneficiary.

A project this size can go over budget very quickly.

If household size is similar for your unit and the tenant's unit, half of the bills should be fine.

I'd say a solid volume of comps, and factor in rate differences, capex upgrades & basic things like inferiority or superiority of the locations assuming price per sq ft, size, etc. are comparable.

Provided a suitable down-size from our old home, with the ability to generate cash flow after we move out in a few years.

The size of the property will impact both budgets.

You can make minor adjustments based on the type of appliances (dishwasher, clothes washer and dryer, air conditioning, etc.) and the size of the rental.

It needs to be a sublease agreement, and unfortunately there is no one size fits all option from the Chicago Association of Realtors.  

Luckily, in my state we have some decent sized good brokerages that do just that.