The seller states that there are no electric or plumbing issues.My question is, could this be worth pursuing or a complete no-go in your professional opinion?

 (2) Applied knowledge is power.

The county condemned it because he change the gas to electric and never pull permits to do so. 

Roof was done as well as HVAC plumbing and electric.

I will manage these buildings, I currently manage another 4 unit building in the same area and know with updates the total rents could increase $3-4$k/yr.Current Rents:  $3900/mo $46,800/yearVacancy: 10% $4,680/yr (actual vacancy rate for area is below 5%)Taxes: $3838/yrInsurance: $2840/yr for cash value not replacement cost (getting more quotes)Maintenance: $4500/yrUtilities: $6,500 (owner currently pays common electric, sewer/trash, and buildings are on well so softener salt and electricity for water pumps.)Budgeting $5k/yr for capexLeaves: $19,442 for debt and cash flow

That way I can tell if the power is on or not.

And of course this doesn't answer your fundamental question which is about the staying power of the Denver Market.  

Are there any value add opportunities such as individually metering each unit, for water and/ or electricity, so the tenants pay these expenses and not the landlord, or is the property already individually metered?

The lot is serviced by municipal water and sewer, and electric is on the road.  

If the exterior looks good, the walls, flooring, countertops, electrical and plumbing look, as yours most likely do, recently replaced or repaired, then you have done what you can to ensure your maximum return.