I'm self employed with my wife as my business partner so no problem with the balance on that part of the spectrum you aske about because we determine how hard we work "balanced" with everything else.

Mold can be treated, so replacing everything needs to be determined.

IMHO, I think that the first home in your portfolio is going to determine the strength and ability to grow as time goes on.

According to the IRS, it is considered "like-kind" to other real property, so that is not an issue.

Unless the rest of the tile is solid and that's the only trouble spot, and that would take some technical knowhow to determine (AND is unlikely), the wisest long-term solution is usually to bring the tile up and start again.

@Agyei Axum To determine rents for the rooms I look at the rooms for rent section of Craigslist and zoom into my neighborhood using the Map View of the listings and look at the competition at that moment. 

How can I best determine ARV without similar comps? 

It appears that the income is the most determining factor. 

I have determined my weaknesses are sales (selling myself) and networking (building relationships).

And you need to seriously re-evaluate your method of determining ARV or repair estimates - whichever one seemed off.