I'm brand new in my journey to build something great.

Geico/Progressive do not offer them - they offer homeowner's insurance, condo insurance, renter's insurance and etc, but none of them covers the building structure & the common areas. 

If the price to replace is within budget I'd do it because you're putting out a newer/safer/more reliable product.2) Cost to replace the entire systems is tough to gauge without knowing the building size and style...

I have a lot of experience in single-family and  large apartment communities and syndications.

I can't tell you how many times I've gone to the property and it is gone, or you figure out something is wrong, maybe the legal description, or the address, or there is $100,000 worth of junk there you need to haul off that was not in the pictures, or that cool commercial building, that when you get there has the faint words that you can now make out to be a former dry cleaner, or gas stations, or lead smelter, or oil change shop or something like that. 

Build a Strong Team:Surround yourself with a reliable team, including a real estate agent, contractor, property manager, and accountant.

Ultimately, section 8 housing can be a great way to build your rental units due to guaranteed income.

These buildings typically have 3 floors with 2 units per floor.

I have decent reserves, but it wouldn't hurt to build them up a little more before considering paying down the mortgage. 

There's a building in Farmington Hills for sale that's already set up to be assisted living.