If you lay tiles or laminate or LVP, this is a must. 

The BP calculator does not know unique location dynamics, supply and demand, redevelopment, gentrification, demographic patterns, job and population growth or lack of, schools, crime...you get the picture.

Also, prepare to rip out carpets and pads, dropped ceiling tiles if you have them, and do a lot of cleaning, especially around the windows.Since I've gone non-smoking with all my properties, my turnover costs and tenant drama have gone way down. 

Based on my own rehabs I would focus on Painting, Drywall hanging and repair, Vanity installation, laminate/luxury vinyl tile installation, ceiling fan and light installation, baseboard and door trim installation, window installation.

I need something that looks like tile for both areas since I already have hardwoods.

Laminate, Luxury Vinyl Plank, Engineered Wood, Tile, etc...

It's 2018... days of damaged roofs due to solar installs are long gone (unless you have a ceramic tile roof or something that easily breaks when stepped on)You can easily reduce your power bill down to just the utility's basic charge, typically 5-10 bucks per month.

-His units are not renovated:  original kitchens; original bathrooms; one has some pretty messed up carpet and older vinyl flooring; other unit has 4 year old carpet and tile; new furnaces, A/C units and windows in both units 4 years ago.

for the wainscoating you could use the sheets from home depot that come in 4'x8' sheets I think they are 1/8" or 3/16 thick and pretty cheap, maybe 20 bucks a sheet. cap it on the top like traditional wainscoating. for backsplash use either tile or or linoleum. the wainscoating can be put right on top with some liquid nails and finish nails and the tile could be put right on top.

The investors I know doing it for many decades over follow a similar pattern.