This can lead to resentment if you don't get ahead of these issues. 

When we start the full-gut redo of the 6th unit (which "should" take about a month) I'll probably visit once a week to make sure things are going well.3.

It sounds like you're putting the cart ahead of the horse here.

Any idea of when you will be coming back to visit?

@Jason Mileshko Well you go ahead and do just that then.

Maybe they can track down the 'rogue deposits' grouped but itemized per tenant in an e-mail ahead of time.

My wife and I wanted to get into real estate investing and were living in San Diego, CA where buying a SFR would make us house-poor as properties with an ADU (accessory dwelling unit/granny flat) were incredibly difficult to find and expensive.Therefore we researched other out-of-state markets and decided to visit Colorado Springs, CO.

HOWEVER, in the meantime, said guest can come and just damage non-visiting units freely and I just have to watch?

I frequently visit Rhode Island and drive down to Eastern Connecticut.

Dad passed about 5 years ago so there has been no real upkeep other than during my visits.