I rent to one couple or small family for the full rental period - no less than 2 months and no more than 3 months.

When it comes to these types of auctions by the sheriff, is there a waiting period that must be observed before rehabbing/renting the building post winning the bid?

Intent (which can be read as timing) really matters.

The meters do act up from time to time so you will have to get them swapped out but overall the best we have found.We have also done pro rata bill back but moved most of our parks to Metron.

Rent growth is a function of supply, demand, and interest rates:- I'd ground any forecast by stating I expect national rents to rise on a pace more or less in line with inflation over any long time period. 2-3% per year.

They have had a difficult year and are struggling to make their payments on time each month.

Legal consequences and potential financial loss that could have been avoided with timely updates.2.

Unless you have the rentals paid for by the time you retire, they aren't going to be enough to live off of. 

However, there is no specific holding period contained in the tax code or regulations and there is no "safe harbor." 

Give them notice that their lease will end and you expect them out by a specific date/time.