The entire floor in the kitchen is rotted away do to the roof being in such bad shape it leaked causing the floor joist and sub-flooring below to totally disappear, this is also common in 2 other areas of the house.

Has anyone dealt with a property with sloping floors before?

The bottom is already rented out for 465/ monthI will be living on the top floor. 

In addition to the size of your home, it's an 1895 house without an open floor plan.  

@Steven MitchellCut floor joints?

However, he installs new 30 year architectural shingles, Stainless appliances, hardwood and tile floors, newly painted interior and exteriors, and more.If you are going to own a property on a street of mostly rental homes, I'd suggest that you stand out from the crowd.

If you have floor space, can you put 2 or 3 standard size tanks in series?  

Your looking at properties with that many bedrooms to have mother in law suits on the top floor normally, maybe some smaller side by sides.

Time for the renovation - the two upstairs floors were manageable; time, effort, a lot of paint, and some minor fixes (thanks YouTube!)

I laid my first hardwood floor at age 12 with my dad in my childhood home and realized how much value it added to the house.