Just put a regular old roof on, and replace it every 15-30 years depending on how it holds up.  

It is still not perfect and you will replace and tweak as you go still. 

In my area many old school buildings are being replaced with new schools, contractors and investors are buying up these old schools and turning them into residential apartments and commercial spaces.

The house is not at all live-able, between the mold and just the overall poor conditions of the interior and the roof needs to be replaced, so I think right now we are moving towards not buying it, rather than buy it and sit on it.

~My top is AC, I have already decided I'm replacing the entire unit next time I have a problem.  

Some of the updates I want to make are built-in micro-wave, replace the tile in the kitchen and the carpeting in the living room with all porcelain tile.  

I'm looking to supplement my income by building a rental portfolio then eventually replace my income and retire early in 5-6 years.

Wow mind blown...So what are my real-estate investing interests/goals:-I carry a J-O-B, and haven't considered replacing it with a career in real-estate investing.

The only time I would likely offer a home warranty (especially in this seller's market) would be if I knew major systems were reaching their endlife (HVAC, for example), but did not replace them in my remodel for some reason.

Turns out in the municipality where the building is located you are not allowed to take basic rental units off the market so for every condo you convert you must replace it with another regular apartment unit either within the same vicinity or somewhere within the city limits.