Proceed with caution and extreme due diligence with your numbers.  

I am looking at a few opportunities in the Midwest and the numbers seems to work, my biggest concern is some of them were built in the early 1900s.

Let them know that issues concerning code violations are of concern; cosmetic issues are not. 

The one in the basement is my main concern.  

As many of you know, finding a condo building that permits short-term rentals in Chicago is extremely challenging due to HOA and city restrictions.I just pulled data on a handful of active condo listings where the buildings explicitly allow short-term/Airbnb rentals.

That ‘hands-to-action’ mindset will serve you really well as you transition into flipping full time.Totally hear you on the GC concern — I think almost every investor has a story about at least one tough experience there.

I'm opening my second home and find them extremely rewarding but think I may stop at these two because I am extremely involved in them and am spreading myself too thin I think. 

Is this a concern for other users?

That's huge, and you should be extremely proud of that.

THIS would have extremely value in knowing which direction to go.