It is important to know this going in because you are the most objective now as opposed to when you are in the middle of the negotiation. 50/50 would be good for you considering what he is bringing, so maybe set that as your ideal number and open with it.

You'll probably want to get a structural engineer to make sure it is possible to remove the existing ceiling joists so as not to put too much lateral pressure on the exterior walls, and recommend footing sizes and depths for the piers.

Chicago has tons of triplexes, Lakeland has some duplexes, and we are not opposed to single family homes.

There are plenty of buyers out there who view the rules as mere guidelines as opposed to absolutes. 

This property is in really bad condition and needs extensive exterior and, presumably (boarded up - can't see inside), interior work to bring it up to move in condition. 

Another approach, as the property badly needs a new roof, exterior paint, fencing, etc. is to undertake that work now, if they won't relocate - keeping in mind the right to quiet enjoyment.

Getting engaged in forum discussions as opposed to just browsing makes a big difference in how quickly you learn things (at least for me!).

If no structural repairs or major exterior (roof, siding, etc.), then it is just surface repairs and that is better.

Once I moved back home, I took a job for a big mortgage company and got to see how things worked on the opposing side.

I think that it would be a good idea to invest in buy n hold properties there as oppose to Miami where the market is volatile.