I'm resisting starting over. 

Looks pretty simple to accomplish with RC Channel and 5/8 fire-rated sheetrock.USG Fire-Resistant Assemblies Catalog (English) - SA100

Have your contractor rip out the rotting window trim and install PVC trim instead. its paintable and will resist future moisture.

My rental property went up in flames today.

Do another one, and another.... very safe, small flips...then after 5 years maybe take on a serious flip and get your hands dirty.Sorry to be so blunt, but you are going about this all wrong and will be another one of those 'investors' who just goes 'one and done' and flames out....

A Leather of faux leather is going to be stain resistant which is nice.

Resist the temptation or pressure to make real estate acquisitions based on what you see others doing.

The efficiency of a solar installation is dependent on many factors - location (or average daily sun hours), house orientation (15deg SSE ideally), roof inclination, shade obstructions (on the roof and/or around the house), consumption, components used, inverter or microinverters, hail resistance, warranty, utility payback vs net metering.

Covid became even more gasoline on the flames of excitement.

However, it may be feasible to cut along the grout lines and remove a section of the tile, perhaps a 3'x3' area right inside the entryway, and replace it with a different flooring material that matches the tile but offers enhanced slip resistance.