Using a family address could expose you to unnecessary risks in the event of any legal or financial issues related to the business.Additionally, these virtual offices often provide extra services like mail and package handling, telephone answering services, and access to meeting rooms, making them a more professional and practical solution.

Make the rules such that the tenant, in order to get the extra federal unemployment, must pay at least half of it to rent.

Knowing cap-x projected out years is not an "extra credit" kind of information, it's fundamental necessity. 

Chris would tell him I hadn’t sent the money when Chris actually had gotten money for the rehab at closing, plus extra that I sent for change orders (which had not been done).

I would rent out an extra room, basement and yep, deal with a part time roommate.

It could’ve just be my personality, but I always felt a little reluctant to be extra friendly if the other side did not reciprocate.

One thing that I would like to add to this list is making an investment without having enough extra money to get through the medium times as well as the bad times.

Lets say you needed $100k in financing at 12% + 2 points and it took you a year to rehab and refinance that is an extra $14k + closing costs.2. you mention roof is 18-20k.

It may sound nice to pay a 6% management fee but the extra fees can add up to be more than the other company that charges 10% with no additional fees.

Insurance is expensive, there is a lot of extra maintenance like painting or electric in common areas that don't apply as much with smaller units.