IMHO, a lot more work than investing in single family homes, but with an outsized return on that extra work.Some thoughts based upon what you've said here:It will be very hard to syndicate a deal that's only 6-12 units.

Fresh and clean with large windows and great natural light with new carpet and paint, nice remodeled bathrooms, kitchen and finished basement with extra bedroom and bathroom.

One of my renters is a professional tradesman and he is my extra handyman.

I spoke with the bank about given us an extra month or two before starting to pay the mortgage cos I can not afford to pay two mortgages at the same time.

I spoke with the bank about given us an extra month or two before starting to pay the mortgage cos I can not afford to pay two mortgages at the same time.

What's your return on investment for the extra money needed to do the repairs and bring the property up to date? 

If someone wants to bring in a dog I would charge 100 dollars a month extra.

We are seeing a little extra inventory on the south shore, but mutli's are still in demand.

I take an honest look at what the building can support, give an extra margin of safety, and take out about that much. 

I would update your lease to include fines after an initial warning about leaving trash or personal items in the common space.I wouldn't allow tenants to mail in the rent.I allow them to deposit directly into my account, ACH or Zelle.Maybe get extra trash cans so that they don't have to leave their bagged trash by a full can.