Not sure about Utah law you may want to read about it for your benefit. 

However, the benefit I have right now is the fact that the rents are not yet registered with the town.So keeping the tenants as is with the low rents will set me up for low rent registration.Instead, I would rather get them all out, do the necessary renovation, including separating the boilers, this way each tenant pays their own heat and hot water.

The proper way to have it all done is a forensic engineered cost segregation study, but on a single small rental property the cost-benefit sometimes doesn't make sense.

Worse, if the market crashes now their best case scenario is they buy now for the same price they could have bought for then, but they missed out on the investment return and tax benefits in the mean time.The overall economy at large is pretty strong right now in many areas. 

I feel like the answers you're looking for vary so much from one municipality to the next any advice given from knowledge gained from elsewhere may not be relevant to your situation.

Or is this to something you just gain with experience?

So my long-term capital gain was about $32K. 

How do I gain more investors like this?

And, if you don't mind, please share what you find in case I (and maybe others like myself) can benefit from any clarifying info.

When doing in depth you can also calculate the benefits from tax depreciation and principal reduction.