He bought it and appreciation has treated him very well over the years. 

I will absolutely take into consideration your advice for being steadfast about having strict house rules in order to ensure that my tenants are mindful about treating the property with care.

If you treat people well; then many of them will treat you well, in return.

I will be a passive investor who will finance the flip and my partner will do all the work and we will split profits according to our agreement.My preferable way would be to buy it in the name of the LLC I own 100%, my partner will deal with contractors and does all the work needed, my LLC pays for everything, we sell the property and my LLC pays my partner agreed percentage of the profits as a project management fee.Can I treat the income from such an activity as passive and avoid self employment tax?

Would love to chat with you about your experience and what made you choose those locations etc. if you’re open to lunch it would be my treat!

I just want to treat is as part of my second-floor unit (where I live--there are tenants on the first floor) and AirBNB it.  

.- If you consider these properties belonging to both of you equally, you can form an LLC, treat it as a partnership and transfer your respective properties into this partnership.

Or, if I was going to remodel the unit, or replace the floor regardless of the damage and just because it is old I would not charge a penny.I am quite a bit on the soft side when tenants cause damage and it depends on how the tenant treated my staff and myself.

Put ground contact green treated if replacing bottom plate.  

I had to treat the floor with odor neutralizer and paint it with odor blocking primer.